DISCLAIMER : Please note that blog owner takes no responsibility of any kind for any type of data loss or damage by trying any of the command/method mentioned in this blog. You may use the commands/method/scripts on your own responsibility.If you find something useful, a comment would be appreciated to let other viewers also know that the solution/method work(ed) for you.
Showing posts with label filesystem. Show all posts
Showing posts with label filesystem. Show all posts
Filesystem commands in AIX
lsfs | Lists all filesystems in the /etc/filesystems entry |
lsfs -a | To list all filesystems (default) |
lsfs -q | List all filesystems with detailed info (shows size of FS and LV in it. so we can check whether size of LV=size os FS) |
lsfs -l | Specify the output in list format |
lsfs -c | Specify the output in column format |
lsfs -v jfs | Lists all jfs filesystems |
chfs -a size=24576 /test | Change size of FS /test to 24576(blocks)x 512 bytes (12 MB) |
chfs -a size=+24576 /test | Add 24576(blocks)x512 byte to FS /test |
chfs -a size=+64M /test | Add 64 MB to /test |
chfs -a size=10G /test | fix size of the FS /test to 10 GB |
chfs -m /test /new | Change the mount point from /test to /new |
chfs -A /test | To auto mount the filesystem test |
chfs -d account /test | Remove account attribute of /test.(from /etc/filesystems file) |
chfs -a splitcopy=/backup -a copy=2 /oracle | This will mount the 2nd copy of mirrored filesystem oracle to /backup in read-only mode for backup purpose |
crfs -v jfs2 -g newvg -a size=100M -m /test | Creates FS /test of type jfs in VG newvg of size 100 MB with default LV. |
crfs -v jfs -d /dev/lv00 -m /test | Create FS /test of type jfs on device /dev/lv00 |
rmfs /test | Deletes FS /test and associated LV |
rmfs -r /test | Deletes FS /test its mount point and associated LV |
defragfs /test | To defragment the file system /test |
defragfs -q /test | Display the current defrag status of the file system |
fsck -y n /dev/lv00 | To check the filesystem associated to /dev/lv00 assuming response "yes" |
fsck -p /dev/lv00 | To restore superblock from backup superblock |
Unix filesystems explained
A filesystem is a logical collection of files on a partition or disk. A
partition is a container for information and can span an entire hard
drive if desired.
Everything in Unix is considered to be a file, including physical devices such as DVD-ROMs, USB devices, floppy drives, and so forth.
Unix uses a hierarchical file system structure, much like an
upside-down tree, with root (/) at the base of the file system and all
other directories spreading from there.
A UNIX filesystem is a collection of files and directories that has the following properties:
Everything in Unix is considered to be a file, including physical devices such as DVD-ROMs, USB devices, floppy drives, and so forth.
A UNIX filesystem is a collection of files and directories that has the following properties:
- It has a root directory (/) that contains other files and directories.
- Each file or directory is uniquely identified by its name, the directory in which it resides, and a unique identifier, typically called an inode.
- By convention, the root directory has an inode number of 2 and the lost+found directory has an inode number of 3. Inode numbers 0 and 1 are not used. File inode numbers can be seen by specifying the -i option to ls command.
- It is self contained. There are no dependencies between one filesystem and any other.
Directory | Description |
---|---|
/ | This is the root directory which should contain only the directories needed at the top level of the file structure. |
/bin | This is where the executable files are located. They are available to all user. |
/dev | These are device drivers. |
/etc | Supervisor directory commands, configuration files, disk configuration files, valid user lists, groups, ethernet, hosts, where to send critical messages. |
/lib | Contains shared library files and sometimes other kernel-related files. |
/boot | Contains files for booting the system. |
/home | Contains the home directory for users and other accounts. |
/mnt | Used to mount other temporary file systems, such as cdrom and floppy for the CD-ROM drive and floppy diskette drive, respectively |
/proc | Contains all processes marked as a file by process number or other information that is dynamic to the system. |
/tmp | Holds temporary files used between system boots |
/usr | Used for miscellaneous purposes, or can be used by many users. Includes administrative commands, shared files, library files, and others |
/var | Typically contains variable-length files such as log and print files and any other type of file that may contain a variable amount of data |
/sbin | Contains binary (executable) files, usually for system administration. For example fdisk and ifconfig utlities. |
/kernel | Contains kernel files |