{
    "mode": "man",
    "parameter": "xfs_admin",
    "section": "8",
    "url": "https://www.chedong.com/phpMan.php/man/xfs_admin/8/json",
    "generated": "2026-11-08T02:28:19Z",
    "synopsis": "xfsadmin  [ -eflpu ] [ -O featurelist ] [ -c 0|1 ] [ -L label ] [ -U uuid ] [ -r rtdev ] de‐\nvice [ logdev ]",
    "sections": {
        "NAME": {
            "content": "xfsadmin - change parameters of an XFS filesystem\n",
            "subsections": []
        },
        "SYNOPSIS": {
            "content": "xfsadmin  [ -eflpu ] [ -O featurelist ] [ -c 0|1 ] [ -L label ] [ -U uuid ] [ -r rtdev ] de‐\nvice [ logdev ]",
            "subsections": [
                {
                    "name": "xfs_admin -V",
                    "content": ""
                }
            ]
        },
        "DESCRIPTION": {
            "content": "xfsadmin uses the xfsdb(8) command to modify various parameters of a filesystem.\n\nDevices that are mounted cannot be modified.  Administrators must unmount filesystems  before\nxfsadmin  or xfsdb(8) can convert parameters.  A number of parameters of a mounted filesys‐\ntem can be examined and modified using the xfsgrowfs(8) command.\n\nThe optional logdev parameter specifies the device special file where the filesystem's exter‐\nnal log resides.  This is required only for filesystems that use an external  log.   See  the\nmkfs.xfs -l option, and refer to xfs(5) for a detailed description of the XFS log.\n",
            "subsections": []
        },
        "OPTIONS": {
            "content": "",
            "subsections": [
                {
                    "name": "-e",
                    "content": "abled (for legacy filesystems, it can't be disabled anymore at mkfs time).\n\nThis option only applies to the deprecated V4 format.\n",
                    "flag": "-e"
                },
                {
                    "name": "-f",
                    "content": "vice (see the mkfs.xfs -d file option).\n",
                    "flag": "-f"
                },
                {
                    "name": "-j",
                    "content": "This option only applies to the deprecated V4 format.\n",
                    "flag": "-j"
                },
                {
                    "name": "-l",
                    "content": "",
                    "flag": "-l"
                },
                {
                    "name": "-p",
                    "content": "This option only applies to the deprecated V4 format.\n",
                    "flag": "-p"
                },
                {
                    "name": "-u",
                    "content": "",
                    "flag": "-u"
                },
                {
                    "name": "-c 0",
                    "content": "Lazy-counters may not be disabled on Version 5 superblock filesystems (i.e. those with\nmetadata CRCs enabled).\n\nIn other words, this option only applies to the deprecated V4 format.\n\nThis operation may take quite a bit  of  time  on  large  filesystems  as  the  entire\nfilesystem needs to be scanned when this option is changed.\n\nWith  lazy-counters  enabled, the superblock is not modified or logged on every change\nof the free-space and inode counters. Instead, enough information  is  kept  in  other\nparts  of  the filesystem to be able to maintain the counter values without needing to\nkeep them in the superblock. This gives significant  improvements  in  performance  on\nsome configurations and metadata intensive workloads.\n",
                    "flag": "-c"
                },
                {
                    "name": "-L _",
                    "content": "Set the filesystem label to label.  XFS filesystem labels can be at most 12 characters\nlong;  if  label  is longer than 12 characters, xfsadmin will truncate it and print a\nwarning message.  The filesystem label can be cleared using the special \"--\" value for\nlabel.\n",
                    "flag": "-L"
                },
                {
                    "name": "-O _",
                    "content": "Add or remove features on an existing V5 filesystem.  The features should be specified\nas a comma-separated list.  status should be either 0 to disable the feature or  1  to\nenable the feature.  Note, however, that most features cannot be disabled.\n\nNOTE:  Administrators  must ensure the filesystem is clean by running xfsrepair -n to\ninspect the filesystem before performing the upgrade.  If corruption is found,  recov‐\nery  procedures (e.g. reformat followed by restoration from backup; or running xfsre‐\npair without the -n) must be followed to clean the filesystem.\n\nSupported features are as follows:\n\ninobtcount\nKeep a count the number of blocks in each inode btree in the  AGI.   This  reduces\nmount time by speeding up metadata space reservation calculations.  The filesystem\ncannot  be downgraded after this feature is enabled.  Once enabled, the filesystem\nwill not be writable by older kernels.  This feature was added to Linux 5.10.\n\nbigtime\nUpgrade a filesystem to support larger  timestamps  up  to  the  year  2486.   The\nfilesystem  cannot be downgraded after this feature is enabled.  Once enabled, the\nfilesystem will not be mountable by older kernels.   This  feature  was  added  to\nLinux 5.10.\n\nnrext64\nUpgrade  a filesystem to support large per-inode extent counters. The maximum data\nfork extent count will be 2^48 - 1, while the maximum attribute fork extent  count\nwill  be  2^32  - 1. The filesystem cannot be downgraded after this feature is en‐\nabled. Once enabled, the filesystem will not be mountable by older kernels.   This\nfeature was added to Linux 5.19.\n",
                    "flag": "-O"
                },
                {
                    "name": "-U _",
                    "content": "Set   the   UUID  of  the  filesystem  to  uuid.   A  sample  UUID  looks  like  this:\n\"c1b9d5a2-f162-11cf-9ece-0020afc76f16\".  The uuid may also be nil, which will set  the\nfilesystem  UUID to the null UUID.  The uuid may also be generate, which will generate\na new UUID for the filesystem.  Note that on CRC-enabled filesystems, this will set an\nincompatible flag such that older kernels will not be able to  mount  the  filesystem.\nTo  remove  this  incompatible flag, use restore, which will restore the original UUID\nand remove the incompatible feature flag as needed.\n",
                    "flag": "-U"
                },
                {
                    "name": "-r _",
                    "content": "Specifies the device special file where the  filesystem's  realtime  section  resides.\nOnly for those filesystems which use a realtime section.\n",
                    "flag": "-r"
                },
                {
                    "name": "-V",
                    "content": "The mount(8) manual entry describes how to mount a filesystem using its label or UUID, rather\nthan its block special device name.\n",
                    "flag": "-V"
                }
            ]
        },
        "SEE ALSO": {
            "content": "mkfs.xfs(8), mount(8), xfsdb(8), xfsgrowfs(8), xfsrepair(8), xfs(5).\n\nxfsadmin(8)",
            "subsections": []
        }
    },
    "summary": "xfsadmin - change parameters of an XFS filesystem",
    "flags": [
        {
            "flag": "-e",
            "long": null,
            "arg": null,
            "description": "abled (for legacy filesystems, it can't be disabled anymore at mkfs time). This option only applies to the deprecated V4 format."
        },
        {
            "flag": "-f",
            "long": null,
            "arg": null,
            "description": "vice (see the mkfs.xfs -d file option)."
        },
        {
            "flag": "-j",
            "long": null,
            "arg": null,
            "description": "This option only applies to the deprecated V4 format."
        },
        {
            "flag": "-l",
            "long": null,
            "arg": null,
            "description": ""
        },
        {
            "flag": "-p",
            "long": null,
            "arg": null,
            "description": "This option only applies to the deprecated V4 format."
        },
        {
            "flag": "-u",
            "long": null,
            "arg": null,
            "description": ""
        },
        {
            "flag": "-c",
            "long": null,
            "arg": null,
            "description": "Lazy-counters may not be disabled on Version 5 superblock filesystems (i.e. those with metadata CRCs enabled). In other words, this option only applies to the deprecated V4 format. This operation may take quite a bit of time on large filesystems as the entire filesystem needs to be scanned when this option is changed. With lazy-counters enabled, the superblock is not modified or logged on every change of the free-space and inode counters. Instead, enough information is kept in other parts of the filesystem to be able to maintain the counter values without needing to keep them in the superblock. This gives significant improvements in performance on some configurations and metadata intensive workloads."
        },
        {
            "flag": "-L",
            "long": null,
            "arg": null,
            "description": "Set the filesystem label to label. XFS filesystem labels can be at most 12 characters long; if label is longer than 12 characters, xfsadmin will truncate it and print a warning message. The filesystem label can be cleared using the special \"--\" value for label."
        },
        {
            "flag": "-O",
            "long": null,
            "arg": null,
            "description": "Add or remove features on an existing V5 filesystem. The features should be specified as a comma-separated list. status should be either 0 to disable the feature or 1 to enable the feature. Note, however, that most features cannot be disabled. NOTE: Administrators must ensure the filesystem is clean by running xfsrepair -n to inspect the filesystem before performing the upgrade. If corruption is found, recov‐ ery procedures (e.g. reformat followed by restoration from backup; or running xfsre‐ pair without the -n) must be followed to clean the filesystem. Supported features are as follows: inobtcount Keep a count the number of blocks in each inode btree in the AGI. This reduces mount time by speeding up metadata space reservation calculations. The filesystem cannot be downgraded after this feature is enabled. Once enabled, the filesystem will not be writable by older kernels. This feature was added to Linux 5.10. bigtime Upgrade a filesystem to support larger timestamps up to the year 2486. The filesystem cannot be downgraded after this feature is enabled. Once enabled, the filesystem will not be mountable by older kernels. This feature was added to Linux 5.10. nrext64 Upgrade a filesystem to support large per-inode extent counters. The maximum data fork extent count will be 2^48 - 1, while the maximum attribute fork extent count will be 2^32 - 1. The filesystem cannot be downgraded after this feature is en‐ abled. Once enabled, the filesystem will not be mountable by older kernels. This feature was added to Linux 5.19."
        },
        {
            "flag": "-U",
            "long": null,
            "arg": null,
            "description": "Set the UUID of the filesystem to uuid. A sample UUID looks like this: \"c1b9d5a2-f162-11cf-9ece-0020afc76f16\". The uuid may also be nil, which will set the filesystem UUID to the null UUID. The uuid may also be generate, which will generate a new UUID for the filesystem. Note that on CRC-enabled filesystems, this will set an incompatible flag such that older kernels will not be able to mount the filesystem. To remove this incompatible flag, use restore, which will restore the original UUID and remove the incompatible feature flag as needed."
        },
        {
            "flag": "-r",
            "long": null,
            "arg": null,
            "description": "Specifies the device special file where the filesystem's realtime section resides. Only for those filesystems which use a realtime section."
        },
        {
            "flag": "-V",
            "long": null,
            "arg": null,
            "description": "The mount(8) manual entry describes how to mount a filesystem using its label or UUID, rather than its block special device name."
        }
    ],
    "examples": [],
    "see_also": [
        {
            "name": "mkfs.xfs",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/mkfs.xfs/8/json"
        },
        {
            "name": "mount",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/mount/8/json"
        },
        {
            "name": "xfsdb",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/xfsdb/8/json"
        },
        {
            "name": "xfsgrowfs",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/xfsgrowfs/8/json"
        },
        {
            "name": "xfsrepair",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/xfsrepair/8/json"
        },
        {
            "name": "xfs",
            "section": "5",
            "url": "https://www.chedong.com/phpMan.php/man/xfs/5/json"
        },
        {
            "name": "xfsadmin",
            "section": "8",
            "url": "https://www.chedong.com/phpMan.php/man/xfsadmin/8/json"
        }
    ]
}