Note: The information contained in this article is structured as help information for the System Management Interface Tool (SMIT) and is not intended for general reading.
A file system is a hierarchical structure (file tree) of files and directories. This type of structure resembles an inverted tree with the roots at the top and the branches at the bottom. This file tree uses directories to organize data and programs into groups, allowing the management of several directories and files at one time.
Lists all file systems as well as displays characteristics of file systems, such as name, mount point, type, size, and automatic mounts.
Displays characteristics of file systems, such as mount points, automatic mounts, permissions, and file system size.
You can add, change, show, or delete any of the file system types the operating system supports. These include the following:
You can add, change, show, or delete any of the file system types the operating system supports. These include the following:
You can add, change, show, or delete any of the file system types the operating system supports. These include the following:
This file system uses database journaling techniques to maintain its structural consistency. This prevents damage to the file system when the system is halted abnormally.
Creates a file system on a logical volume within a previously created volume group. A new logical volume is created for the file system.
Specifies the volume group on which to create the file system. A volume group is a collection of one or more physical volumes.
Specifies the volume group on which to create the file system. A volume group is a collection of one or more physical volumes.
Specifies the physical partition size of the Journaled File System in 512-byte blocks. If the specified size is not evenly divisible by the physical partition size, it is rounded up to the next number that is.
The maximum size of a JFS file system is a function of it number of bits per i-node (NBPI) value:
NBPI - Maximum size in 512-byte blocks
512 - 16777216
1024 - 33554432
2048 - 67108864
4096 - 134217728.
Specifies the mount point, which is the directory where the file system is available or will be made available.
Specifies the mount point, which is the directory where the file system is available or will be made available.
Specifies whether the file system is mounted at each system restart. Possible values are:
Specifies whether the file system is mounted at each system restart. Possible values are:
Sets the permissions for the file system.
Specifies security-related mount options. The possible values are:
Enables disk accounting on this file system.
Specifies the file system fragment size. The value parameter must be either 512, 1024, 2048, or 4096. The default fragment size is 4096 bytes.
A file system fragment is the smallest unit of disk storage that can be allocated to a file. If your system has a large number of small files, decreasing the fragment size will increase the efficiency of disk utilization. However, decreasing the fragment size could also decrease file access efficiency.
Specifies the ratio of file system size in bytes to the number of i-nodes. Increasing the number of bytes per i-node (NBPI) decreases the total number of i-nodes in a file system.
The Allocation Group size determines the allowable range of NBPI values for a file system according to the following table:
Allocation Group Size NBPI Range
8 512, 1024, 2048, 4096, 8192, 16384
16 1024, 2048, 4096, 8192, 16384, 32768
32 2048, 4096, 8192, 16384, 32768, 65536
64 4096, 8192, 16384, 32768, 65536, 131072 .
Selects a compression algorithm for the file system. Possible choices are:
no - Creates a file system that does not use data compression. The default is no.
LZ - Create a file system in which all data is automatically compressed using LZ compression before being written to disk and is automatically uncompressed when read from disk. Requires a fragment size of less than 4096 bytes.
NOTE: A file system that has been created using LZ cannot be changed to no.
Adds a journaled file system (JFS) to an existing logical volume. The size of the file system will be the size of the logical volume. All data on the target logical volume will be destroyed.
Specifies the name of an existing logical volume. Enter the name of a logical volume or use the List feature to select from a list of previously defined logical volumes.
Note: All data on this logical volume will be destroyed.
Specifies the name of an existing logical volume. Click on the List button to select from a list of previously defined logical volumes.
Note: All data on the selected logical volume will be destroyed.
Displays file system attributes and allows certain attributes to be modified.
Removes a file system, any logical volume on which it resides, and the associated stanza in the /etc/filesystems file.
Specifies the file system to be removed.
Specifies the file system to be removed.
Selecting yes removes the mount point (directory) where the file system is normally made available.
NOTE: The directory is removed only if it is empty.
Makes a CD-ROM file system available by adding an appropriate stanza to the /etc/filesystems file. This eases management of the CD-ROM file systems.
Removes a CD-ROM file system and the associated stanza in the /etc/filesystems file.
Specifies the device name of the CD-ROM device.
Attempts to reduce external fragmentation by reallocating disk blocks and consolidating small unusable holes of disk space into larger contiguous free space. The defragmentation utility offers these options:
External file system fragmentation occurs when files are allocated and deleted; this can produce small holes of free disk space that are not contiguous. These holes may be too small to satisfy a given allocation request. In extreme cases, this can result in a file system with a large percentage of its free space occupying holes that are essentially unusable.
Instructs the operating system to make a file system available for use at a specified location (the mount point).
Mounts a file system expressed as a device (for example, /dev/hd6). Use the SMIT List function to obtain a list of file systems.
The directory specified becomes the root directory of the newly mounted file system. Use the SMIT List function to obtain a list of file systems.
Requests a forced mount during system initialization to enable mounting over the root file system.
Specifies the remote node that holds the directory to be mounted.
Mounts a file system as a removable file system. While there are open files on it, a removable mounted file system behaves the same as a normally mounted file system. However, when there are no open files (and while no process has a current directory on the file system), all of the file system disk buffers in the file system are written to the medium, and the operating system forgets the structure of the file system.
Mounts a file system as a read-only file system, regardless of its previous specification.
Specifies device access from this mount. Possible options are yes and no. Selecting yes prevents opens of devices from this mount.
Specifies whether execution of setuid and setgid programs are allowed from this mount. Possible options are yes and no. Selecting yes prevents execution of these programs from this mount.
Mounts all stanzas in the /etc/filesystems file that contain the type=Type attribute and are not mounted.
Specifies the name of the group.
Unmounts a previously mounted file system, directory, or file. Members of the system group and users operating with root user authority can unmount any mounted directory. Other users can unmount any directory or file if they have write permission to the mounted-over directory or file.
Note: SMIT will not unmount the /usr/lpp/info/$LANG directory, the directory on which SMIT helps are located. Typically, this is the CD-ROM.
Unmounts all mounted file systems, except those with stanzas in the /etc/filesystems file with the mount=automatic attribute.
Unmounts all remotely mounted file systems.
To unmount local mounts, you can specify the device, directory, file, or file system on which it is mounted.
Specifies the node holding the mounted directory you want to unmount.
Unmounts all stanzas in the /etc/filesystems file that contain the type=Type flag and are mounted.
Checks for file system inconsistencies. You must be able to read the device file that the file system resides on (for example, the /dev/lv00 device). Normally, the file system is consistent, and this option merely reports on the number of files, used blocks, and free blocks in the file system. If the file system is inconsistent, this option displays information about the inconsistencies found.
Any inconsistencies reported and not fixed by this SMIT menu interface must be addressed by running fsck interactively from the command line.
Specifies the file system to verify. If you do not specify a file system, the /etc/filesystems file is examined to find a list of file systems to check by default. This option can perform simultaneous checks on multiple file systems. This can reduce the time required to check a large number of file systems.
Performs a fast check. Under normal circumstances, the only file systems likely to be affected by halting the system without shutting down properly are those that are mounted when the system stops.
Specifies a file parameter as a scratch file on a file system other than the one being checked.
Creates copies of your files on a backup medium, such as a magnetic tape or diskette. The copies are in one of the two following backup formats:
Creates a copy of your file system on a backup medium, such as a magnetic tape or diskette. The copy is in backup-by-i-node format.
Specifies the file system to be backed up.
Specifies the output device to which the file system is backed up.
Specifies the level of backup to create. Enter 0 for a full backup, or a numeral from 1 to 9 for an incremental backup. A level n backup will back up all files modified since the most recent level n-1 (or lower) backup. For instance, a level 3 backup will back up all files modified since the most recent level 2 backup. The default backup level is 0.
Specifies whether or not to record the current backup in /etc/dumpdates. Selecting yes saves information needed for maintaining incremental backups. The default is no.
Restore files backed up on a local system.
Restores contents of a file system backup (also known as a backup by i-node).
Specifies the input device. Specify the device parameter as a file name (such as the /dev/rmt0 file) to get input from the named device, or specify - (minus) to get input from the standard input device.
Specifies the directory from which to begin the restore. You must be at the top of the file system you are restoring; for example, if you are restoring /home, you must be in /home.
Specifies whether to produce verbose output.
Specifies the number of 512-byte blocks to read in a single input operation. If you do not specify this flag, the restore command selects a default value appropriate for the physical device you have selected. Larger values of the blocks parameter result in larger physical transfers from tape devices.
Lists the contents of a backup. The backup can be in either backup-by-i-node format or backup-by-name format.
You can back up files and directories to an archive, or you can restore or list contents of an archive.
Creates copies of your files, directories, or both on a backup medium, such as a magnetic tape or diskette. The copies (or archive) are in back-up-by-name format.
Specifies one or more files, directories, or both to back up. Enter . (period) to back up everything in the current working directory (as specified in the Current Working Directory field). Backing up a directory recursively backs up the contents of that directory including all subdirectories.
Specifies the directory from which to begin the backup. This allows for specifying path names relative to the current working directory to back up.
Specifies whether to back up all files, or just those files belonging to a Journaled File System (JFS).
Specifies whether to attempt to pack (compress) files before placing them in the archive. Some files cannot be compressed and will be placed in the archive as is. Restoring the archive will automatically unpack files packed by this option.
Restore the contents of an archive in back-up-by-name format.
Specifies a particular file or directory to restore. Leave this entry blank to restore the entire archive. The file or directory name given must match the name stored in the archive. Use the List Contents of a Backup menu option to determine file or directory names in a particular archive.
Specify the file system fragment size in bytes. Decreasing the fragment size below a full block (4096 bytes) allows partial blocks to be allocated at the end of a file. You can set the fragment size to 512, 1024, 2048, or 4096 bytes. If a file system is compressed, you must specify a fragment size of 512, 1024, or 2048 bytes.
Creates a file system. The resulting file system is compatible with the AIX Version 3 file system if you accept the default values for fragment size, number of bytes per i-node (NBPI), and allocation group size and if the file system size remains below 2GB.
Creates a file system in which all data is compressed automatically using LZ compression before being written to disk and all data is uncompressed automatically when read from disk.
Creates a file system in which the maximum file size is increased from 2GB to 64GB minus 124MB.
Specify the size of the journaled file system in 512-byte blocks. If the specified size is not evenly divisible by the physical partition size, it is rounded up to the next number that is evenly divisible by the physical partition size.
Enables large files for the file system.
Specifies whether the file system is mounted at each system restart. Possible values are:
Specifies whether the file system is mounted at each system restart. Possible values are:
Back up only files that have been modified since a specific full backup (an incremental backup).
The possible levels are 0 to 9. If you do not supply a level, the default is 9. A level 0 backup includes all files on the file system. An n level backup includes all files modified since the last n - 1 level backup.
The physical device name (the block or raw name), the name of the directory on which the file system is normally mounted, or the name of any other directory.
Specifies the name of the file system or the directory within the file system to be backed up.
Specifies the number of 512-byte blocks to write in a single output operation, referred to as the block size. If a number is not specified, the backup command uses a default value appropriate for the physical device selected. Larger values result in larger physical transfers to tape devices.
Running the backup command results in the loss of all material previously stored on the selected output medium.
Limits the total number of blocks to use on the backup medium. Use this attribute for diskette devices only. This option is ignored when performing i-node backups.
Causes the backup command to display a report on each phase of the backup as it is completed and gives regular progress reports during the longest phase.
You can set or change a file system's size, permissions, mount point, and automatic mounts.
Specifies the name of the file system, expressed as a mount point.
Specifies the name of the file system, expressed as a mount point.
Specifies the name of the file system, expressed as a mount point.
Specifies the name of the file system, expressed as a mount point.
Specifies the new mount point.
Specifies the new mount point.
Sets the permissions for the file system:
ro - Specifies read-only permissions.
rw - Specifies read-write permissions.
Specifies the mount group. Mount groups are used to group related mounts so that they can be mounted as one instead of mounting each individually. For example, if several scratch file systems always need to be mounted together when performing certain tests, they can each be placed in the test mount group.
Specifies the mount group. Mount groups are used to group related mounts so that they can be mounted as one instead of mounting each individually. For example, if several scratch file systems always need to be mounted together when performing certain tests, they can each be placed in the test mount group.
This file system uses database journaling techniques to keep its structure consistent. This prevents damage to the file system if the system is halted abnormally. The enhanced JFS supports both 32-bit and 64-bit file system semantics. It supports 4 petabyte file systems and dynamically allocates inodes so that disk space is not wasted on unused inodes.
Adds an enhanced journaled file system (JFS2) and creates a new logical volume for it.
Adds an enhanced journaled file system (JFS2) to an existing logical volume. The size of the file system is the size of the logical volume. All data on the target logical volume is destroyed.