xref: /linux/Documentation/admin-guide/jfs.rst (revision 26fbb4c8c7c3ee9a4c3b4de555a8587b5a19154e)
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2IBM's Journaled File System (JFS) for Linux
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4
5JFS Homepage:  http://jfs.sourceforge.net/
6
7The following mount options are supported:
8
9(*) == default
10
11iocharset=name
12                Character set to use for converting from Unicode to
13		ASCII.  The default is to do no conversion.  Use
14		iocharset=utf8 for UTF-8 translations.  This requires
15		CONFIG_NLS_UTF8 to be set in the kernel .config file.
16		iocharset=none specifies the default behavior explicitly.
17
18resize=value
19                Resize the volume to <value> blocks.  JFS only supports
20		growing a volume, not shrinking it.  This option is only
21		valid during a remount, when the volume is mounted
22		read-write.  The resize keyword with no value will grow
23		the volume to the full size of the partition.
24
25nointegrity
26                Do not write to the journal.  The primary use of this option
27		is to allow for higher performance when restoring a volume
28		from backup media.  The integrity of the volume is not
29		guaranteed if the system abnormally abends.
30
31integrity(*)
32                Commit metadata changes to the journal.  Use this option to
33		remount a volume where the nointegrity option was
34		previously specified in order to restore normal behavior.
35
36errors=continue
37                        Keep going on a filesystem error.
38errors=remount-ro(*)
39                        Remount the filesystem read-only on an error.
40errors=panic
41                        Panic and halt the machine if an error occurs.
42
43uid=value
44                Override on-disk uid with specified value
45gid=value
46                Override on-disk gid with specified value
47umask=value
48                Override on-disk umask with specified octal value. For
49                directories, the execute bit will be set if the corresponding
50		read bit is set.
51
52discard=minlen, discard/nodiscard(*)
53                This enables/disables the use of discard/TRIM commands.
54		The discard/TRIM commands are sent to the underlying
55                block device when blocks are freed. This is useful for SSD
56                devices and sparse/thinly-provisioned LUNs.  The FITRIM ioctl
57		command is also available together with the nodiscard option.
58		The value of minlen specifies the minimum blockcount, when
59		a TRIM command to the block device is considered useful.
60		When no value is given to the discard option, it defaults to
61		64 blocks, which means 256KiB in JFS.
62		The minlen value of discard overrides the minlen value given
63		on an FITRIM ioctl().
64
65The JFS mailing list can be subscribed to by using the link labeled
66"Mail list Subscribe" at our web page http://jfs.sourceforge.net/
67