FILESYSTEMS(5,F) AIX Technical Reference FILESYSTEMS(5,F) ------------------------------------------------------------------------------- filesystems PURPOSE Centralizes file system characteristics. DESCRIPTION A file system is a complete directory structure, including a root directory and any directories and files beneath it. A file system is confined to a single partition. All of the information about the file system is centralized in the filesystems file. Most of the file system maintenance commands take their defaults from this file. The file is organized into stanzas whose names are file system names and whose contents are attribute-value pairs specifying characteristics of the file system. The filesystems file serves two purposes: o It documents the layout characteristics of the file systems. o It frees the person who sets up the file system from having to enter and remember items such as the device where the file system resides because this information is defined in the file. If the Transparent Computing Facility is installed, there is a unique /etc/filesystems for each cluster site (/etc/filesystems is a symbolic link into the local file system). File System Attributes Each stanza names the directory (which must be the full pathname) where the file system is normally mounted. The attributes specify all of the parameters of the file system. See "attributes" for the format of an attribute file. The attributes currently used are: account Used by the dodisk command to determine the file systems to be processed by the accounting system. This value can be either TRUE or FALSE. backupden Used by the backup command to determine the density of the default backup device associated with each file system. Density is measured in bytes per inch. The parameter is ignored for diskettes. backupdev Used by the backup and restore commands to determine the default output device associated with each file system. The value of this keyword is usually the name of a diskette or magnetic tape special file. Processed April 1, 1992 FILESYSTEMS(5,F) 1 FILESYSTEMS(5,F) AIX Technical Reference FILESYSTEMS(5,F) backuplen Used by the backup command to determine the size of the default backup device associated with each file system. The size of a tape is measured in tracks times feet. For example, the backuplen for a 300-foot 9-track tape is 2700. This parameter is ignored for diskettes. backuplev Used by the backup command to determine the default backup level to take for each file system. Backup levels are discussed in the backup command. bad List of physically flawed disk blocks which are excluded from the pool of available file system blocks. boot Used by the mkfs command to initialize the boot block of a new file system. This specifies the name of the load module to be placed into the first block of the file system. check Used by the fsck command to determine the default file systems to be checked. TRUE enables checking while FALSE disables checking. If a number, rather than TRUE is specified, the number indicates which of multiple concurrent fsck processes will check this file system. This parallel checking, described in fsck command in AIX Operating System Commands Reference, permits multiple file systems to be checked in parallel when multiple drives exist. cyl Used by the mkfs command to initialize the free list and super block of a new file system. The value is the number of blocks in one cylinder. It defines the size of an interleave cluster. dev Identifies, for local mounts, the block special file where the file system resides. System management utilities use this attribute to map file system names to the corresponding device names. For NFS mounts, the host:NFSdir form is used. Host specifies the host machine on which the remote file system resides. NFSdir specifies the path name of the remote file system being mounted. Use ASCII characters for filesystem name to ensure successful communication across different locales. free Used by the df command to determine which file systems are to have their free space displayed by default. This value is either TRUE or FALSE. freq Used by the dumpbsd command, freq specifies dump frequency, indicated by number of days. ftype File system type. May include one of the following values: nfs An NFS mounted file system. Processed April 1, 1992 FILESYSTEMS(5,F) 2 FILESYSTEMS(5,F) AIX Technical Reference FILESYSTEMS(5,F) nonrepl A standard file system which is not replicated on other sites. This filesystem is accessible by other sites in a TCF cluster only when the machine storing it is up. repl A filesystem which is one instance of multiple copies throughout a TCF cluster. The following value is used to differentiate between system and user replicated file systems: user This filesystem is user replicated. If this value is not present, the file system is system replicated. One of the following may also be present: primary This is the primary copy of the replicated file system, readable and writable by all sites in the TCF cluster. backbone A backup copy of a replicated filesystem, readable by all sites, but writable only by the primary site. System replicated filesystems which are not primary or backbone must include the following: fstore An fstore value found in /ect/fstore which indicates what files are present on this secondary copy. gfs Global file system number. Used by TCF. Every minidisk on a node has a different gfs number. gfspack Global file system. Always 1 for nonreplicated file systems. Used by TCF. inodes Used by the mkfs command for reference and to build the file system. The value is the number of inodes (files) in the file system. If this attribute is not specified, the value is calculated from the size attribute. mode Used by the dumpbsd command, mode specifies the type of file system desired, as follows: rw Read/write device ro Read only device sw Swap device Processed April 1, 1992 FILESYSTEMS(5,F) 3 FILESYSTEMS(5,F) AIX Technical Reference FILESYSTEMS(5,F) nm File system normally not mounted xx Ignore type. mount Used by the mount command to determine whether or not this file system should be mounted by default. The possible values of mount are: automatic Automatically mounts a filesystem when the system is rebooted. For example, in the sample file, the root file system is mount=automatic. This means the root file system mounts automatically when the system is rebooted. The TRUE value is not used so that mount all does not try to mount it. Also, the value is not FALSE because certain utilities, such as ncheck normally avoid file systems with a value of mount=false. false This file system is not mounted by default. true This file system is mounted by the mount all (or mount -a) command. After a value of true or false, the following can be specified: readonly The filesystem is mount read-only by default. options See -o options in the MOUNT command in AIX Operating System Commands Reference. site The name of the machine that contains the minidisk. size Used by the mkfs command for reference and to build the file system. The value is the number of blocks in the file system. Note: The maximum number of blocks is 2097152. (This would be a file system with 2 gigabytes.) skip Used by the mkfs command to initialize the free list and super block of a new file system. The value is the number of blocks to skip when the free list is interleaved. This number is processor- and device-specific. swap Used by the swapon command for adding secondary swap/page devices. Secondary page devices can be used to augment the primary page device defined during system installation and dynamically increase the system page space. See the example section for a sample swap definition. type Used by the mount command to determine whether or not this file system should be mounted. When the command "mount -t" string is issued, all of the currently unmounted file systems with a type equal to string are mounted. Processed April 1, 1992 FILESYSTEMS(5,F) 4 FILESYSTEMS(5,F) AIX Technical Reference FILESYSTEMS(5,F) vol Used by the mkfs command when initializing the label on a new file system. The value is a volume or pack label using a maximum of eight characters. The file system label is always the stanza name. quotas Used to mark which file system will be affected when a -a flag is specified with a quotaon, quotaoff, quotacheck, or repquota command. If the value is "on", the file system is affected. Otherwise, it is ignored. EXAMPLE * * File system information * default: vol = "AIX" mount = false check = false free = false backupdev =/dev/fd0 backuplen = 1440 /u1: dev = /dev/hd1 vol = "/u1" mount = true check = 1 gfs = 2 gfspack = 1 size = 12000 ftype = nonrepl free = true site = aixps /aixps: dev = /dev/hd2 vol = "/aixps" mount = automatic check = 0 gfs = 3 gfspack = 1 size = 6000 ftype = nonrepl free = true site = aixps /: Processed April 1, 1992 FILESYSTEMS(5,F) 5 FILESYSTEMS(5,F) AIX Technical Reference FILESYSTEMS(5,F) dev = /dev/hd3 vol = "/" mount = automatic check = 0 gfs = 1 gfspack = 1 size = 50000 ftype = repl,primary free = true site = aixps * /aixps/tmp: dev = /dev/hd6 vol = "/aixps/tmp" mount = true check = 1 gfs = 4 gfspack = 1 size = 4000 ftype = nonrepl free = true site = aixps * /ul/aixps2: dev = "aixps2:/ul" vol = "/ul/aixps2" options = "rw,intr,bg" gfs = 101 mount = false checks = false free = true type = nfs_mount ftype = nfs site = aixps swaphd7: dev = /dev/hd7 swap = true check = false mount = false site = aixps FILE /etc/filesystems RELATED INFORMATION In this book: "attributes" and "fs." The backup, df, dumpbsd, dumpcfg, fsck, mkfs, mount, restore, swapon, and Processed April 1, 1992 FILESYSTEMS(5,F) 6 FILESYSTEMS(5,F) AIX Technical Reference FILESYSTEMS(5,F) umount commands in AIX Operating System Commands Reference. "Managing the IBM AIX Network File System" chapter in the AIX Operating System Managing Guide. Processed April 1, 1992 FILESYSTEMS(5,F) 7