1xfs_admin(8) System Manager's Manual xfs_admin(8)
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6 xfs_admin - change parameters of an XFS filesystem
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9 xfs_admin [ -eflu ] [ -c 0|1 ] [ -L label ] [ -U uuid ] device
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12 xfs_admin uses the xfs_db(8) command to modify various parameters of a
13 filesystem.
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15 Devices that are mounted cannot be modified. Administrators must
16 unmount filesystems before xfs_admin or xfs_db(8) can convert parame‐
17 ters. A number of parameters of a mounted filesystem can be examined
18 and modified using the xfs_growfs(8) command.
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21 -e Enables unwritten extent support on a filesystem that does not
22 already have this enabled (for legacy filesystems, it can't be
23 disabled anymore at mkfs time).
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25 -f Specifies that the filesystem image to be processed is stored in
26 a regular file at device (see the mkfs.xfs -d file option).
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28 -j Enables version 2 log format (journal format supporting larger
29 log buffers).
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31 -l Print the current filesystem label.
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33 -u Print the current filesystem UUID (Universally Unique IDenti‐
34 fier).
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36 -c 0|1 [22mEnable (1) or disable (0) lazy-counters in the filesystem. This
37 operation may take quite a bit of time on large filesystems as
38 the entire filesystem needs to be scanned when this option is
39 changed.
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41 With lazy-counters enabled, the superblock is not modified or
42 logged on every change of the free-space and inode counters.
43 Instead, enough information is kept in other parts of the
44 filesystem to be able to maintain the counter values without
45 needing to keep them in the superblock. This gives significant
46 improvements in performance on some configurations and metadata
47 intensive workloads.
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49 -L label
50 Set the filesystem label to label. XFS filesystem labels can be
51 at most 12 characters long; if label is longer than 12 charac‐
52 ters, xfs_admin will truncate it and print a warning message.
53 The filesystem label can be cleared using the special "--" value
54 for label.
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56 -U uuid
57 Set the UUID of the filesystem to uuid. A sample UUID looks
58 like this: "c1b9d5a2-f162-11cf-9ece-0020afc76f16". The uuid may
59 also be nil, which will set the filesystem UUID to the null
60 UUID. The uuid may also be generate, which will generate a new
61 UUID for the filesystem.
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63 The mount(8) manual entry describes how to mount a filesystem using its
64 label or UUID, rather than its block special device name.
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67 mkfs.xfs(8), mount(8), xfs_db(8), xfs_growfs(8), xfs_repair(8), xfs(5).
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71 xfs_admin(8)