ufsis one of the primary default disk-based file systems for illumos. The UFS file system is hierarchical, starting with its root directory (/) and continuing downward through a number of directories. The root of a UFS file system is inode 2. A UFS file system's root contents replace the contents of the directory upon which it is mounted.
Subsequent sections of this manpage provide details of the UFS file systems.
FSOKAY -fs_time. fs_time is the timestamp that indicates when the last system write occurred. fs_state is updated whenever fs_clean changes. Some fs_clean values are:
FSBAD. A non-logging file system can have
It is not necessary to run the fsck command
on unmounted file systems with a state of
ENOSPC if an attempt is made to mount a UFS file
system with a state of
FSACTIVE for read/write
As an additional safeguard, fs_clean
should be trusted only if fs_state contains a
value equal to
FSOKAY is a
constant integer defined in the
/usr/include/sys/fs/ufs_fs.h file. Otherwise,
fs_clean is treated as though it contains the
If a UID or GID contains an extended value, the short variable (ic_suid, ic_sgid) contains the value 65535 and the corresponding UID or GID is in ic_uid or ic_gid. Because numbers for block and character devices are stored in the first direct block pointer of the inode (ic_db) and the disk block addresses are already 32 bit values, no special encoding exists for device numbers (unlike UID or GID fields).
On-disk format changes for a multiterabyte UFS file system include:
MTB_UFS_MAGIC. For more information, see the /usr/include/sys/fs/ufs_fs.h file.
UFS logging provides two advantages:
The UFS log is allocated from free blocks on the file system and is sized at approximately 1 Mbyte per 1 Gbyte of file system, up to 256 Mbytes. The log size may be larger (up to a maximum of 512 Mbytes), depending upon the number of cylinder groups present in the file system. The log is continually flushed as it fills up. The log is also flushed when the file system is unmounted or as a result of a lockfs(1M) command.
# mount -F ufs /dev/dsk/c0t0d0s7 /export/home
/dev/dsk/c0t0d0s7 /dev/rdsk/c0t0d0s7 /export/home ufs 2 yes -
For more information on mounting UFS file systems, see mount_ufs(1M).
-voption. In the fstyp output, look at the nbfree (number of blocks free) and nffree ((number of fragments free)) fields. On unmounted filesystems, you can use fsck(1M) and observe the last line of output, which reports, among other items, the number of fragments and the degree of fragmentation. To correct a fragmentation problem, run ufsdump(1M) and ufsrestore(1M) on the ufs filesystem.
|November 29, 2021||OmniOS|