This is am-utils.info, produced by makeinfo version 4.1 from am-utils.texi. INFO-DIR-SECTION Administration START-INFO-DIR-ENTRY * Am-utils: (am-utils). The Amd automounter suite of utilities END-INFO-DIR-ENTRY  File: am-utils.info, Node: FSinfo errors, Prev: FSinfo Command Line Options, Up: FSinfo Errors produced by FSinfo ========================= The following table documents the errors and warnings which FSinfo may produce. " expected Occurs if an unescaped newline is found in a quoted string. ambiguous mount: VOLUME is a replicated filesystem If several filesystems are declared as having the same volume name, they will be considered replicated filesystems. To mount a replicated filesystem statically, a specific host will need to be named, to say which particular copy to try and mount, else this error will result. can't open FILENAME for writing Occurs if any errors are encountered when opening an output file. cannot determine localname since volname VOLUME is not uniquely defined If a volume is replicated and an attempt is made to mount the filesystem statically without specifying a local mountpoint, FSinfo cannot calculate a mountpoint, as the desired pathname would be ambiguous. DEVICE has duplicate exportfs data Produced if the `exportfs' option is used multiple times within the same branch of a filesystem definition. For example, if you attempt to set the `exportfs' data at different levels of the mountpoint directory tree. dump frequency for HOST:DEVICE is non-zero Occurs if DEVICE has its `fstype' declared to be `swap' or `export' and the `dump' option is set to a value greater than zero. Swap devices should not be dumped. duplicate host HOSTNAME! If a host has more than one definition. end of file within comment A comment was unterminated before the end of one of the configuration files. FILENAME: cannot open for reading If a file specified on the command line as containing configuration data could not be opened. FILESYSTEM has a volname but no exportfs data Occurs when a volume name is declared for a file system, but the string specifying what machines the filesystem can be exported to is missing. fs field "FIELD-NAME" already set Occurs when multiple definitions are given for one of the attributes of a host's filesystem. host field "FIELD-NAME" already set If duplicate definitions are given for any of the fields with a host definition. HOST:DEVICE has more than one mount point Occurs if the mount option for a host's filesystem specifies multiple trees at which to place the mountpoint. HOST:DEVICE has no mount point Occurs if the `mount' option is not specified for a host's filesystem. HOST:DEVICE needs field "FIELD-NAME" Occurs when a filesystem is missing a required field. FIELD-NAME could be one of `fstype', `opts', `passno' or `mount'. HOST:mount field specified for swap partition Occurs if a mountpoint is given for a filesystem whose type is declared to be `swap'. malformed IP dotted quad: ADDRESS If the Internet address of an interface is incorrectly specified. An Internet address definition is handled to inet_addr(3N) to see if it can cope. If not, then this message will be displayed. malformed netmask: NETMASK If the netmask cannot be decoded as though it were a hexadecimal number, then this message will be displayed. It will typically be caused by incorrect characters in the NETMASK value. mount field "FIELD-NAME" already set Occurs when a static mount has multiple definitions of the same field. mount tree field "FIELD-NAME" already set Occurs when the FIELD-NAME is defined more than once during the definition of a filesystems mountpoint. netif field FIELD-NAME already set Occurs if you attempt to define an attribute of an interface more than once. network booting requires both root and swap areas Occurs if a machine has mount declarations for either the root partition or the swap area, but not both. You cannot define a machine to only partially boot via the network. no disk mounts on HOSTNAME If there are no static mounts, nor local disk mounts specified for a machine, this message will be displayed. no volname given for HOST:DEVICE Occurs when a filesystem is defined to be mounted on `default', but no volume name is given for the file system, then the mountpoint cannot be determined. not allowed '/' in a directory name Occurs when a pathname with multiple directory elements is specified as the name for an automounter tree. A tree should only have one name at each level. pass number for HOST:DEVICE is non-zero Occurs if DEVICE has its `fstype' declared to be `swap' or `export' and the fsck(8) pass number is set. Swap devices should not be fsck'd. *Note FSinfo fstype Option::. sub-directory DIRECTORY of DIRECTORY-TREE starts with '/' Within the filesystem specification for a host, if an element DIRECTORY of the mountpoint begins with a `/' and it is not the start of the tree. sub-directory of DIRECTORY-TREE is named "default" `default' is a keyword used to specify if a mountpoint should be automatically calculated by FSinfo. If you attempt to specify a directory name as this, it will use the filename of `default' but will produce this warning. unknown \ sequence Occurs if an unknown escape sequence is found inside a string. Within a string, you can give the standard C escape sequences for strings, such as newlines and tab characters. unknown directory attribute If an unknown keyword is found while reading the definition of a host's filesystem mount option. unknown filesystem attribute Occurs if an unrecognized keyword is used when defining a host's filesystems. unknown host attribute Occurs if an unrecognized keyword is used when defining a host. unknown mount attribute Occurs if an unrecognized keyword is found while parsing the list of static mounts. unknown volname VOLUME automounted [ on name ] Occurs if VOLUME is used in a definition of an automount map but the volume name has not been declared during the host filesystem definitions. volname VOLUME is unknown Occurs if an attempt is made to mount or reference a volume name which has not been declared during the host filesystem definitions. volname VOLUME not exported from MACHINE Occurs if you attempt to mount the volume VOLUME from a machine which has not declared itself to have such a filesystem available.  File: am-utils.info, Node: Hlfsd, Next: Assorted Tools, Prev: FSinfo, Up: Top Hlfsd ***** Hlfsd is a daemon which implements a filesystem containing a symbolic link to subdirectory within a user's home directory, depending on the user which accessed that link. It was primarily designed to redirect incoming mail to users' home directories, so that it can be read from anywhere. It was designed and implemented by Erez Zadok and Alexander Dupuy , at the Computer Science Department (http://www.cs.columbia.edu/) of Columbia University (http://www.columbia.edu/). A paper (http://www.cs.columbia.edu/~ezk/research/hlfsd/hlfsd.html) on Hlfsd was presented at the Usenix LISA VII conference in 1993. Hlfsd operates by mounting itself as an NFS server for the directory containing linkname, which defaults to `/hlfs/home'. Lookups within that directory are handled by Hlfsd, which uses the password map to determine how to resolve the lookup. The directory will be created if it doesn't already exist. The symbolic link will be to the accessing user's home directory, with subdir appended to it. If not specified, subdir defaults to `.hlfsdir'. This directory will also be created if it does not already exist. A `SIGTERM' sent to Hlfsd will cause it to shutdown. A `SIGHUP' will flush the internal caches, and reload the password map. It will also close and reopen the log file, to enable the original log file to be removed or rotated. A `SIGUSR1' will cause it to dump its internal table of user IDs and home directories to the file `/tmp/hlfsddump'. * Menu: * Introduction to Hlfsd:: * Background to Mail Delivery:: * Using Hlfsd::  File: am-utils.info, Node: Introduction to Hlfsd, Next: Background to Mail Delivery, Prev: Hlfsd, Up: Hlfsd Introduction to Hlfsd ===================== Electronic mail has become one of the major applications for many computer networks, and use of this service is expected to increase over time, as networks proliferate and become faster. Providing a convenient environment for users to read, compose, and send electronic mail has become a requirement for systems administrators (SAs). Widely used methods for handling mail usually require users to be logged into a designated "home" machine, where their mailbox files reside. Only on that one machine can they read newly arrived mail. Since users have to be logged into that system to read their mail, they often find it convenient to run all of their other processes on that system as well, including memory and CPU-intensive jobs. For example, in our department, we have allocated and configured several multi-processor servers to handle such demanding CPU/memory applications, but these were underutilized, in large part due to the inconvenience of not being able to read mail on those machines. (No home directories were located on these designated CPU-servers, since we did not want NFS service for users' home directories to have to compete with CPU-intensive jobs. At the same time, we discouraged users from running demanding applications on their home machines.) Many different solutions have been proposed to allow users to read their mail on any host. However, all of these solutions fail in one or more of several ways: * they introduce new single points of failure * they require using different mail transfer agents (MTAs) or user agents (UAs) * they do not solve the problem for all cases, i.e. the solution is only partially successful for a particular environment. We have designed a simple filesystem, called the "Home-Link File System", to provide the ability to deliver mail to users' home directories, without modification to mail-related applications. We have endeavored to make it as stable as possible. Of great importance to us was to make sure the HLFS daemon, `hlfsd' , would not hang under any circumstances, and would take the next-best action when faced with problems. Compared to alternative methods, Hlfsd is a stable, more general solution, and easier to install/use. In fact, in some ways, we have even managed to improve the reliability and security of mail service. Our server implements a small filesystem containing a symbolic link to a subdirectory of the invoking user's home directory, and named symbolic links to users' mailbox files. The Hlfsd server finds out the UID of the process that is accessing its mount point, and resolves the pathname component `home' as a symbolic link to a subdirectory within the home directory given by the UID's entry in the password file. If the GID of the process that attempts to access a mailbox file is a special one (called HLFS_GID), then the server maps the name of the _next_ pathname component directly to the user's mailbox. This is necessary so that access to a mailbox file by users other than the owner can succeed. The server has safety features in case of failures such as hung filesystems or home directory filesystems that are inaccessible or full. On most of our machines, mail gets delivered to the directory `/var/spool/mail'. Many programs, including UAs, depend on that path. Hlfsd creates a directory `/mail', and mounts itself on top of that directory. Hlfsd implements the path name component called `home', pointing to a subdirectory of the user's home directory. We have made `/var/spool/mail' a symbolic link to `/mail/home', so that accessing `/var/spool/mail' actually causes access to a subdirectory within a user's home directory. The following table shows an example of how resolving the pathname `/var/mail/NAME' to `/users/ezk/.mailspool/NAME' proceeds. Resolving Component Pathname left to resolve Value if symbolic link / var/mail/NAME var/ mail/NAME mail@ /mail/home/NAME mail@ -> /mail/home / mail/home/NAME mail/ home/NAME home@ NAME home@ -> /users/ezk/.mailspool / users/ezk/.mailspool/NAME users/ ezk/.mailspool/NAME ezk/ .mailspool/NAME .mailspool/ NAME NAME  File: am-utils.info, Node: Background to Mail Delivery, Next: Using Hlfsd, Prev: Introduction to Hlfsd, Up: Hlfsd Background to Mail Delivery =========================== This section provides an in-depth discussion of why available methods for delivering mail to home directories are not as good as the one used by Hlfsd. * Menu: * Single-Host Mail Spool Directory:: * Centralized Mail Spool Directory:: * Distributed Mail Spool Service:: * Why Deliver Into the Home Directory?::  File: am-utils.info, Node: Single-Host Mail Spool Directory, Next: Centralized Mail Spool Directory, Prev: Background to Mail Delivery, Up: Background to Mail Delivery Single-Host Mail Spool Directory -------------------------------- The most common method for mail delivery is for mail to be appended to a mailbox file in a standard spool directory on the designated "mail home" machine of the user. The greatest advantage of this method is that it is the default method most vendors provide with their systems, thus very little (if any) configuration is required on the SA's part. All they need to set up are mail aliases directing mail to the host on which the user's mailbox file is assigned. (Otherwise, mail is delivered locally, and users find mailboxes on many machines.) As users become more sophisticated, and aided by windowing systems, they find themselves logging in on multiple hosts at once, performing several tasks concurrently. They ask to be able to read their mail on any host on the network, not just the one designated as their "mail home".  File: am-utils.info, Node: Centralized Mail Spool Directory, Next: Distributed Mail Spool Service, Prev: Single-Host Mail Spool Directory, Up: Background to Mail Delivery Centralized Mail Spool Directory -------------------------------- A popular method for providing mail readability from any host is to have all mail delivered to a mail spool directory on a designated "mail-server" which is exported via NFS to all of the hosts on the network. Configuring such a system is relatively easy. On most systems, the bulk of the work is a one-time addition to one or two configuration files in `/etc'. The file-server's spool directory is then hard-mounted across every machine on the local network. In small environments with only a handful of hosts this can be an acceptable solution. In our department, with a couple of hundred active hosts and thousands of mail messages processed daily, this was deemed completely unacceptable, as it introduced several types of problems: Scalability and Performance As more and more machines get added to the network, more mail traffic has to go over NFS to and from the mail-server. Users like to run mail-watchers, and read their mail often. The stress on the shared infrastructure increases with every user and host added; loads on the mail server would most certainly be high since all mail delivery goes through that one machine.(1) This leads to lower reliability and performance. To reduce the number of concurrent connections between clients and the server host, some SAs have resorted to automounting the mail-spool directory. But this solution only makes things worse: since users often run mail watchers, and many popular applications such as `trn', `emacs', `csh' or `ksh' check periodically for new mail, the automounted directory would be effectively permanently mounted. If it gets unmounted automatically by the automounter program, it is most likely to get mounted shortly afterwards, consuming more I/O resources by the constant cycle of mount and umount calls. Reliability The mail-server host and its network connectivity must be very reliable. Worse, since the spool directory has to be hard-mounted,(2) many processes which access the spool directory (various shells, `login', `emacs', etc.) would be hung as long as connectivity to the mail-server is severed. To improve reliability, SAs may choose to backup the mail-server's spool partition several times a day. This may make things worse since reading or delivering mail while backups are in progress may cause backups to be inconsistent; more backups consume more backup-media resources, and increase the load on the mail-server host. ---------- Footnotes ---------- (1) Delivery via NFS-mounted filesystems may require usage of `rpc.lockd' and `rpc.statd' to provide distributed file-locking, both of which are widely regarded as unstable and unreliable. Furthermore, this will degrade performance, as local processes as well as remote `nfsd' processes are kept busy. (2) No SA in their right minds would soft-mount read/write partitions -- the chances for data loss are too great.  File: am-utils.info, Node: Distributed Mail Spool Service, Next: Why Deliver Into the Home Directory?, Prev: Centralized Mail Spool Directory, Up: Background to Mail Delivery Distributed Mail Spool Service ------------------------------ Despite the existence of a few systems that support delivery to users' home directories, mail delivery to home directories hasn't caught on. We believe the main reason is that there are too many programs that "know" where mailbox files reside. Besides the obvious (the delivery program `/bin/mail' and mail readers like `/usr/ucb/Mail', `mush', `mm', etc.), other programs that know mailbox location are login, from, almost every shell, `xbiff', `xmailbox', and even some programs not directly related to mail, such as `emacs' and `trn'. Although some of these programs can be configured to look in different directories with the use of environment variables and other resources, many of them cannot. The overall porting work is significant. Other methods that have yet to catch on require the use of a special mail-reading server, such as IMAP or POP. The main disadvantage of these systems is that UAs need to be modified to use these services -- a long and involved task. That is why they are not popular at this time. Several other ideas have been proposed and even used in various environments. None of them is robust. They are mostly very specialized, inflexible, and do not extend to the general case. Some of the ideas are plain bad, potentially leading to lost or corrupt mail: automounters Using an automounter such as Amd to provide a set of symbolic links from the normal spool directory to user home directories is not sufficient. UAs rename, unlink, and recreate the mailbox as a regular file, therefore it must be a real file, not a symbolic link. Furthermore, it must reside in a real directory which is writable by the UAs and MTAs. This method may also require populating `/var/spool/mail' with symbolic links and making sure they are updated. Making Amd manage that directory directly fails, since many various lock files need to be managed as well. Also, Amd does not provide all of the NFS operations which are required to write mail such as write, create, remove, and unlink. `$MAIL' Setting this variable to an automounted directory pointing to the user's mail spool host only solves the problem for those programs which know and use `$MAIL'. Many programs don't, therefore this solution is partial and of limited flexibility. Also, it requires the SAs or the users to set it themselves -- an added level of inconvenience and possible failures. /bin/mail Using a different mail delivery agent could be the solution. One such example is `hdmail'. However, `hdmail' still requires modifying all UAs, the MTA's configuration, installing new daemons, and changing login scripts. This makes the system less upgradable or compatible with others, and adds one more complicated system for SAs to deal with. It is not a complete solution because it still requires each user have their `$MAIL' variable setup correctly, and that every program use this variable.  File: am-utils.info, Node: Why Deliver Into the Home Directory?, Prev: Distributed Mail Spool Service, Up: Background to Mail Delivery Why Deliver Into the Home Directory? ------------------------------------ There are several major reasons why SAs might want to deliver mail directly into the users' home directories: Location Many mail readers need to move mail from the spool directory to the user's home directory. It speeds up this operation if the two are on the same filesystem. If for some reason the user's home directory is inaccessible, it isn't that useful to be able to read mail, since there is no place to move it to. In some cases, trying to move mail to a non-existent or hung filesystem may result in mail loss. Distribution Having all mail spool directories spread among the many more filesystems minimizes the chances that complete environments will grind to a halt when a single server is down. It does increase the chance that there will be someone who is not able to read their mail when a machine is down, but that is usually preferred to having no one be able to read their mail because a centralized mail server is down. The problem of losing some mail due to the (presumably) higher chances that a user's machine is down is minimized in HLFS. Security Delivering mail to users' home directories has another advantage -- enhanced security and privacy. Since a shared system mail spool directory has to be world-readable and searchable, any user can see whether other users have mail, when they last received new mail, or when they last read their mail. Programs such as `finger' display this information, which some consider an infringement of privacy. While it is possible to disable this feature of `finger' so that remote users cannot see a mailbox file's status, this doesn't prevent local users from getting the information. Furthermore, there are more programs which make use of this information. In shared environments, disabling such programs has to be done on a system-wide basis, but with mail delivered to users' home directories, users less concerned with privacy who do want to let others know when they last received or read mail can easily do so using file protection bits. In summary, delivering mail to home directories provides users the functionality sought, and also avoids most of the problems just discussed.  File: am-utils.info, Node: Using Hlfsd, Prev: Background to Mail Delivery, Up: Hlfsd Using Hlfsd =========== * Menu: * Controlling Hlfsd:: * Hlfsd Options:: * Hlfsd Files::  File: am-utils.info, Node: Controlling Hlfsd, Next: Hlfsd Options, Prev: Using Hlfsd, Up: Using Hlfsd Controlling Hlfsd ----------------- Much the same way Amd is controlled by `ctl-amd', so does Hlfsd get controlled by the `ctl-hlfsd' script: ctl-hlfsd start Start a new Hlfsd. ctl-hlfsd stop Stop a running Hlfsd. ctl-hlfsd restart Stop a running Hlfsd, wait for 10 seconds, and then start a new one. It is hoped that within 10 seconds, the previously running Hlfsd terminate properly; otherwise, starting a second one could cause system lockup. For example, on our systems, we start Hlfsd within `ctl-hlfsd' as follows on Solaris 2 systems: hlfsd -a /var/alt_mail -x all -l /var/log/hlfsd /mail/home .mailspool The directory `/var/alt_mail' is a directory in the root partition where alternate mail will be delivered into, when it cannot be delivered into the user's home directory. Normal mail gets delivered into `/var/mail', but on our systems, that is a symbolic link to `/mail/home'. `/mail' is managed by Hlfsd, which creates a dynamic symlink named `home', pointing to the subdirectory `.mailspool' _within_ the accessing user's home directory. This results in mail which normally should go to `/var/mail/`$USER'', to go to ``$HOME'/.mailspool/`$USER''. Hlfsd does not create the `/var/mail' symlink. This needs to be created (manually) once on each host, by the system administrators, as follows: mv /var/mail /var/alt_mail ln -s /mail/home /var/mail  File: am-utils.info, Node: Hlfsd Options, Next: Hlfsd Files, Prev: Controlling Hlfsd, Up: Using Hlfsd Hlfsd Options ------------- -a ALT_DIR Alternate directory. The name of the directory to which the symbolic link returned by Hlfsd will point, if it cannot access the home directory of the user. This defaults to `/var/hlfs'. This directory will be created if it doesn't exist. It is expected that either users will read these files, or the system administrators will run a script to resend this "lost mail" to its owner. -c CACHE-INTERVAL Caching interval. Hlfsd will cache the validity of home directories for this interval, in seconds. Entries which have been verified within the last CACHE-INTERVAL seconds will not be verified again, since the operation could be expensive, and the entries are most likely still valid. After the interval has expired, Hlfsd will re-verify the validity of the user's home directory, and reset the cache time-counter. The default value for CACHE-INTERVAL is 300 seconds (5 minutes). -f Force fast startup. This option tells Hlfsd to skip startup-time consistency checks such as existence of mount directory, alternate spool directory, symlink to be hidden under the mount directory, their permissions and validity. -g GROUP Set the special group HLFS_GID to GROUP. Programs such as `/usr/ucb/from' or `/usr/sbin/in.comsat', which access the mailboxes of other users, must be setgid `HLFS_GID' to work properly. The default group is `hlfs'. If no group is provided, and there is no group `hlfs', this feature is disabled. -h Help. Print a brief help message, and exit. -i RELOAD-INTERVAL Map-reloading interval. Each RELOAD-INTERVAL seconds, Hlfsd will reload the password map. Hlfsd needs the password map for the UIDs and home directory pathnames. Hlfsd schedules a `SIGALRM' to reload the password maps. A `SIGHUP' sent to Hlfsd will force it to reload the maps immediately. The default value for RELOAD-INTERVAL is 900 seconds (15 minutes.) -l LOGFILE Specify a log file to which Hlfsd will record events. If LOGFILE is the string `syslog' then the log messages will be sent to the system log daemon by syslog(3), using the `LOG_DAEMON' facility. This is also the default. -n No verify. Hlfsd will not verify the validity of the symbolic link it will be returning, or that the user's home directory contains sufficient disk-space for spooling. This can speed up Hlfsd at the cost of possibly returning symbolic links to home directories which are not currently accessible or are full. By default, Hlfsd validates the symbolic-link in the background. The `-n' option overrides the meaning of the `-c' option, since no caching is necessary. -o MOUNT-OPTIONS Mount options which Hlfsd will use to mount itself on top of DIRNAME. By default, MOUNT-OPTIONS is set to `ro'. If the system supports symbolic-link caching, default options are set to `ro,nocache'. -p Print PID. Outputs the process-id of Hlfsd to standard output where it can be saved into a file. -v Version. Displays version information to standard error. -x LOG-OPTIONS Specify run-time logging options. The options are a comma separated list chosen from: `fatal', `error', `user', `warn', `info', `map', `stats', `all'. -C Force Hlfsd to run on systems that cannot turn off the NFS attribute-cache. Use of this option on those systems is discouraged, as it may result in loss or misdelivery of mail. The option is ignored on systems that can turn off the attribute-cache. -D LOG-OPTIONS Select from a variety of debugging options. Prefixing an option with the string `no' reverses the effect of that option. Options are cumulative. The most useful option is `all'. Since this option is only used for debugging other options are not documented here. A fuller description is available in the program source. A `SIGUSR1' sent to Hlfsd will cause it to dump its internal password map to the file `/usr/tmp/hlfsd.dump.XXXXXX', where `XXXXXX' will be replaced by a random string generated by mktemp(3) or (the more secure) mkstemp(3). -P PASSWORD-FILE Read the user-name, user-id, and home directory information from the file PASSWORD-FILE. Normally, Hlfsd will use getpwent(3) to read the password database. This option allows you to override the default database, and is useful if you want to map users' mail files to a directory other than their home directory. Only the username, uid, and home-directory fields of the file PASSWORD-FILE are read and checked. All other fields are ignored. The file PASSWORD-FILE must otherwise be compliant with Unix Version 7 colon-delimited format passwd(4).  File: am-utils.info, Node: Hlfsd Files, Prev: Hlfsd Options, Up: Using Hlfsd Hlfsd Files ----------- The following files are used by Hlfsd: `/hlfs' directory under which Hlfsd mounts itself and manages the symbolic link `home'. `.hlfsdir' default sub-directory in the user's home directory, to which the `home' symbolic link returned by Hlfsd points. `/var/hlfs' directory to which `home' symbolic link returned by Hlfsd points if it is unable to verify the that user's home directory is accessible. For discussion on other files used by Hlfsd, see *Note lostaltmail::, and *Note lostaltmail.conf-sample::.  File: am-utils.info, Node: Assorted Tools, Next: Examples, Prev: Hlfsd, Up: Top Assorted Tools ************** The following are additional utilities and scripts included with am-utils, and get installed. * Menu: * am-eject:: * amd.conf-sample:: * amd2ldif:: * amd2sun:: * automount2amd:: * ctl-amd:: * ctl-hlfsd:: * expn:: * fix-amd-map:: * fixmount:: * fixrmtab:: * lostaltmail:: * lostaltmail.conf-sample:: * mk-amd-map:: * pawd:: * redhat-ctl-amd:: * wait4amd:: * wait4amd2die:: * wire-test::  File: am-utils.info, Node: am-eject, Next: amd.conf-sample, Prev: Assorted Tools, Up: Assorted Tools am-eject ======== A shell script unmounts a floppy or CD-ROM that is automounted, and then attempts to eject the removable device.  File: am-utils.info, Node: amd.conf-sample, Next: amd2ldif, Prev: am-eject, Up: Assorted Tools amd.conf-sample =============== A sample Amd configuration file. *Note Amd Configuration File::.  File: am-utils.info, Node: amd2ldif, Next: amd2sun, Prev: amd.conf-sample, Up: Assorted Tools amd2ldif ======== A script to convert Amd maps to LDAP input files. Use it as follows: amd2ldif mapname base < amd.mapfile > mapfile.ldif  File: am-utils.info, Node: amd2sun, Next: automount2amd, Prev: amd2ldif, Up: Assorted Tools amd2sun ======= A script to convert Amd maps to Sun Automounter maps. Use it as follows amd2sun < amd.mapfile > auto_mapfile  File: am-utils.info, Node: automount2amd, Next: ctl-amd, Prev: amd2sun, Up: Assorted Tools automount2amd ============= A script to convert old Sun Automounter maps to Amd maps. Say you have the Sun automount file auto.foo, with these two lines: home earth:/home moon -ro,intr server:/proj/images Running automount2amd auto.foo > amd.foo will produce the Amd map amd.foo with this content: # generated by automount2amd on Sat Aug 14 17:59:32 US/Eastern 1999 /defaults \\ type:=nfs;opts:=rw,grpid,nosuid,utimeout=600 home \ host==earth;type:=link;fs:=/home \\ rhost:=earth;rfs:=/home moon \ -addopts:=ro,intr \\ host==server;type:=link;fs:=/proj/images \\ rhost:=server;rfs:=/proj/images This perl script will use the following /default entry type:=nfs;opts:=rw,grpid,nosuid,utimeout=600 If you wish to override that, define the $DEFAULTS environment variable, or modify the script. If you wish to generate Amd maps using the hostd (*note hostd Selector Variable::) Amd map syntax, then define the environment variable $DOMAIN or modify the script. Note that automount2amd does not understand the syntax in newer Sun Automount maps, those used with autofs.  File: am-utils.info, Node: ctl-amd, Next: ctl-hlfsd, Prev: automount2amd, Up: Assorted Tools ctl-amd ======= A script to start, stop, or restart Amd. Use it as follows: ctl-amd start Start a new Amd process. ctl-amd stop Stop the running Amd. ctl-amd restart Stop the running Amd (if any), safely wait for it to terminate, and then start a new process -- only if the previous one died cleanly. *Note Run-time Administration::, for more details.  File: am-utils.info, Node: ctl-hlfsd, Next: expn, Prev: ctl-amd, Up: Assorted Tools ctl-hlfsd ========= A script for controlling Hlfsd, much the same way `ctl-amd' controls Amd. Use it as follows: ctl-hlfsd start Start a new Hlfsd process. ctl-hlfsd stop Stop the running Hlfsd. ctl-hlfsd restart Stop the running Hlfsd (if any), wait for 10 seconds for it to terminate, and then start a new process -- only if the previous one died cleanly. *Note Hlfsd::, for more details.  File: am-utils.info, Node: expn, Next: fix-amd-map, Prev: ctl-hlfsd, Up: Assorted Tools expn ==== A script to expand email addresses into their full name. It is generally useful when using with the `lostaltmail' script, but is a useful tools otherwise. $ expn -v ezk@cs.columbia.edu ezk@cs.columbia.edu -> ezk@shekel.mcl.cs.columbia.edu ezk@shekel.mcl.cs.columbia.edu -> Erez Zadok <"| /usr/local/mh/lib/slocal -user ezk || exit 75> Erez Zadok <\ezk> Erez Zadok  File: am-utils.info, Node: fix-amd-map, Next: fixmount, Prev: expn, Up: Assorted Tools fix-amd-map =========== Am-utils changed some of the syntax and default values of some variables. For example, the default value for `${os}' for Solaris 2.x (aka SunOS 5.x) systems used to be `sos5', it is now more automatically generated from `config.guess' and its value is `sunos5'. This script converts older Amd maps to new ones. Use it as follows: fix-amd-map < old.map > new.map  File: am-utils.info, Node: fixmount, Next: fixrmtab, Prev: fix-amd-map, Up: Assorted Tools fixmount ======== `fixmount' is a variant of showmount(8) that can delete bogus mount entries in remote mountd(8) daemons. This is useful to cleanup otherwise ever-accumulating "junk". Use it for example: fixmount -r host See the online manual page for `fixmount' for more details of its usage.  File: am-utils.info, Node: fixrmtab, Next: lostaltmail, Prev: fixmount, Up: Assorted Tools fixrmtab ======== A script to invalidate `/etc/rmtab' entries for hosts named. Also restart mountd for changes to take effect. Use it for example: fixrmtab host1 host2 ...  File: am-utils.info, Node: lostaltmail, Next: lostaltmail.conf-sample, Prev: fixrmtab, Up: Assorted Tools lostaltmail =========== A script used with Hlfsd to resend any "lost" mail. Hlfsd redirects mail which cannot be written into the user's home directory to an alternate directory. This is useful to continue delivering mail, even if the user's file system was unavailable, full, or over quota. But, the mail which gets delivered to the alternate directory needs to be resent to its respective users. This is what the `lostaltmail' script does. Use it as follows: lostaltmail This script needs a configuration file `lostaltmail.conf' set up with the right parameters to properly work. *Note Hlfsd::, for more details.  File: am-utils.info, Node: lostaltmail.conf-sample, Next: mk-amd-map, Prev: lostaltmail, Up: Assorted Tools lostaltmail.conf-sample ======================= This is a text file with configuration parameters needed for the `lostaltmail' script. The script includes comments explaining each of the configuration variables. See it for more information. Also *note Hlfsd:: for general information.  File: am-utils.info, Node: mk-amd-map, Next: pawd, Prev: lostaltmail.conf-sample, Up: Assorted Tools mk-amd-map ========== This program converts a normal Amd map file into an ndbm database with the same prefix as the named file. Use it as follows: mk-amd-map mapname  File: am-utils.info, Node: pawd, Next: redhat-ctl-amd, Prev: mk-amd-map, Up: Assorted Tools pawd ==== Pawd is used to print the current working directory, adjusted to reflect proper paths that can be reused to go through the automounter for the shortest possible path. In particular, the path printed back does not include any of Amd's local mount points. Using them is unsafe, because Amd may unmount managed file systems from the mount points, and thus including them in paths may not always find the files within. Without any arguments, Pawd will print the automounter adjusted current working directory. With any number of arguments, it will print the adjusted path of each one of the arguments.  File: am-utils.info, Node: redhat-ctl-amd, Next: wait4amd, Prev: pawd, Up: Assorted Tools redhat-ctl-amd ============== This script is similar to ctl-amd (*note ctl-amd::) but is intended for Red Hat Linux systems. You can safely copy redhat-ctl-amd onto `/etc/rc.d/init.d/amd'. The script supplied by Am-utils is usually better than the one provided by Red Hat, because the Red Hat script does not correctly kill Amd processes: it is too quick to kill the wrong processes, leaving stale or hung mount points behind.  File: am-utils.info, Node: wait4amd, Next: wait4amd2die, Prev: redhat-ctl-amd, Up: Assorted Tools wait4amd ======== A script to wait for Amd to start on a particular host before performing an arbitrary command. The command is executed repeatedly, with 1 second intervals in between. You may interrupt the script using `^C' (or whatever keyboard sequence your terminal's `intr' function is bound to). Examples: wait4amd saturn amq -p -h saturn When Amd is up on host `saturn', get the process ID of that running Amd. wait4amd pluto rlogin pluto Remote login to host `pluto' when Amd is up on that host. It is generally necessary to wait for Amd to properly start and initialize on a remote host before logging in to it, because otherwise user home directories may not be accessible across the network. wait4amd pluto A short-hand version of the previous command, since the most useful reason for this script is to login to a remote host. I use it very often when testing out new versions of Amd, and need to reboot hung hosts.  File: am-utils.info, Node: wait4amd2die, Next: wire-test, Prev: wait4amd, Up: Assorted Tools wait4amd2die ============ This script is used internally by `ctl-amd' when used to restart Amd. It waits for Amd to terminate. If it detected that Amd terminated cleanly, this script will return an exist status of zero. Otherwise, it will return a non-zero exit status. The script tests for Amd's existence once every 5 seconds, six times, for a total of 30 seconds. It will return a zero exist status as soon as it detects that Amd dies.  File: am-utils.info, Node: wire-test, Prev: wait4amd2die, Up: Assorted Tools wire-test ========= A simple program to test if some of the most basic networking functions in am-util's library `libamu' work. It also tests the combination of NFS protocol and version number that are supported from the current host, to a remote one. For example, in this test a machine which only supports NFS Version 2 is contacting a remote host that can support the same version, but using both UDP and TCP. If no host name is specified, `wire-test' will try `localhost'. $ wire-test moisil Network name is "mcl-lab-net.cs.columbia.edu" Network number is "128.59.13" Network name is "old-net.cs.columbia.edu" Network number is "128.59.16" My IP address is 0x7f000001. NFS Version and protocol tests to host "moisil"... testing vers=2, proto="udp" -> found version 2. testing vers=3, proto="udp" -> failed! testing vers=2, proto="tcp" -> found version 2. testing vers=3, proto="tcp" -> failed!  File: am-utils.info, Node: Examples, Next: Internals, Prev: Assorted Tools, Up: Top Examples ******** * Menu: * User Filesystems:: * Home Directories:: * Architecture Sharing:: * Wildcard Names:: * rwho servers:: * /vol:: * /defaults with selectors:: * /tftpboot in a chroot-ed environment::  File: am-utils.info, Node: User Filesystems, Next: Home Directories, Prev: Examples, Up: Examples User Filesystems ================ With more than one fileserver, the directories most frequently cross-mounted are those containing user home directories. A common convention used at Imperial College is to mount the user disks under /home/machine. Typically, the `/etc/fstab' file contained a long list of entries such as: machine:/home/machine /home/machine nfs ... for each fileserver on the network. There are numerous problems with this system. The mount list can become quite large and some of the machines may be down when a system is booted. When a new fileserver is installed, `/etc/fstab' must be updated on every machine, the mount directory created and the filesystem mounted. In many environments most people use the same few workstations, but it is convenient to go to a colleague's machine and access your own files. When a server goes down, it can cause a process on a client machine to hang. By minimizing the mounted filesystems to only include those actively being used, there is less chance that a filesystem will be mounted when a server goes down. The following is a short extract from a map taken from a research fileserver at Imperial College. Note the entry for `localhost' which is used for users such as the operator (`opr') who have a home directory on most machine as `/home/localhost/opr'. /defaults opts:=rw,intr,grpid,nosuid charm host!=${key};type:=nfs;rhost:=${key};rfs:=/home/${key} \ host==${key};type:=ufs;dev:=/dev/xd0g # ... # localhost type:=link;fs:=${host} ... # # dylan has two user disks so have a # top directory in which to mount them. # dylan type:=auto;fs:=${map};pref:=${key}/ # dylan/dk2 host!=dylan;type:=nfs;rhost:=dylan;rfs:=/home/${key} \ host==dylan;type:=ufs;dev:=/dev/dsk/2s0 # dylan/dk5 host!=dylan;type:=nfs;rhost:=dylan;rfs:=/home/${key} \ host==dylan;type:=ufs;dev:=/dev/dsk/5s0 ... # toytown host!=${key};type:=nfs;rhost:=${key};rfs:=/home/${key} \ host==${key};type:=ufs;dev:=/dev/xy1g ... # zebedee host!=${key};type:=nfs;rhost:=${key};rfs:=/home/${key} \ host==${key};type:=ufs;dev:=/dev/dsk/1s0 # # Just for access... # gould type:=auto;fs:=${map};pref:=${key}/ gould/staff host!=gould;type:=nfs;rhost:=gould;rfs:=/home/${key} # gummo host!=${key};type:=nfs;rhost:=${key};rfs:=/home/${key} ... This map is shared by most of the machines listed so on those systems any of the user disks is accessible via a consistent name. Amd is started with the following command amd /home amd.home Note that when mounting a remote filesystem, the "automounted" mount point is referenced, so that the filesystem will be mounted if it is not yet (at the time the remote `mountd' obtains the file handle).  File: am-utils.info, Node: Home Directories, Next: Architecture Sharing, Prev: User Filesystems, Up: Examples Home Directories ================ One convention for home directories is to locate them in `/homes' so user `jsp''s home directory is `/homes/jsp'. With more than a single fileserver it is convenient to spread user files across several machines. All that is required is a mount-map which converts login names to an automounted directory. Such a map might be started by the command: amd /homes amd.homes where the map `amd.homes' contained the entries: /defaults type:=link # All the entries are of type:=link jsp fs:=/home/charm/jsp njw fs:=/home/dylan/dk5/njw ... phjk fs:=/home/toytown/ai/phjk sjv fs:=/home/ganymede/sjv Whenever a login name is accessed in `/homes' a symbolic link appears pointing to the real location of that user's home directory. In this example, `/homes/jsp' would appear to be a symbolic link pointing to `/home/charm/jsp'. Of course, `/home' would also be an automount point. This system causes an extra level of symbolic links to be used. Although that turns out to be relatively inexpensive, an alternative is to directly mount the required filesystems in the `/homes' map. The required map is simple, but long, and its creation is best automated. The entry for `jsp' could be: jsp -sublink:=${key};rfs:=/home/charm \ host==charm;type:=ufs;dev:=/dev/xd0g \ host!=charm;type:=nfs;rhost:=charm This map can become quite big if it contains a large number of entries. By combining two other features of Amd it can be greatly simplified. First the UFS partitions should be mounted under the control of `/etc/fstab', taking care that they are mounted in the same place that Amd would have automounted them. In most cases this would be something like `/a/"host"/home/"host"' and `/etc/fstab' on host `charm' would have a line: /dev/xy0g /a/charm/home/charm 4.2 rw,nosuid,grpid 1 5 The map can then be changed to: /defaults type:=nfs;sublink:=${key};opts:=rw,intr,nosuid,grpid jsp rhost:=charm;rfs:=/home/charm njw rhost:=dylan;rfs:=/home/dylan/dk5 ... phjk rhost:=toytown;rfs:=/home/toytown;sublink:=ai/${key} sjv rhost:=ganymede;rfs:=/home/ganymede This map operates as usual on a remote machine (ie `${host}' not equal to `${rhost}'). On the machine where the filesystem is stored (ie `${host}' equal to `${rhost}'), Amd will construct a local filesystem mount point which corresponds to the name of the locally mounted UFS partition. If Amd is started with the `-r' option then instead of attempting an NFS mount, Amd will simply inherit the UFS mount (*note Inheritance Filesystem::). If `-r' is not used then a loopback NFS mount will be made. This type of mount is known to cause a deadlock on many systems.