diff options
Diffstat (limited to 'upstream/opensuse-leap-15-6/man8/xfs_scrub.8')
| -rw-r--r-- | upstream/opensuse-leap-15-6/man8/xfs_scrub.8 | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/upstream/opensuse-leap-15-6/man8/xfs_scrub.8 b/upstream/opensuse-leap-15-6/man8/xfs_scrub.8 new file mode 100644 index 00000000..e881ae76 --- /dev/null +++ b/upstream/opensuse-leap-15-6/man8/xfs_scrub.8 @@ -0,0 +1,176 @@ +.TH xfs_scrub 8 +.SH NAME +xfs_scrub \- check and repair the contents of a mounted XFS filesystem +.SH SYNOPSIS +.B xfs_scrub +[ +.B \-abCemnTvx +] +.I mount-point +.br +.B xfs_scrub \-V +.SH DESCRIPTION +.B xfs_scrub +attempts to check and repair all metadata in a mounted XFS filesystem. +.PP +.B WARNING! +This program is +.BR EXPERIMENTAL "," +which means that its behavior and interface +could change at any time! +.PP +.B xfs_scrub +asks the kernel to scrub all metadata objects in the filesystem. +Metadata records are scanned for obviously bad values and then +cross-referenced against other metadata. +The goal is to establish a reasonable confidence about the consistency +of the overall filesystem by examining the consistency of individual +metadata records against the other metadata in the filesystem. +Damaged metadata can be rebuilt from other metadata if there exists +redundant data structures which are intact. +.PP +Filesystem corruption and optimization opportunities will be logged to +the standard error stream. +Enabling verbose mode will increase the amount of status information +sent to the output. +.PP +If the kernel scrub reports that metadata needs repairs or optimizations and +the user does not pass +.B -n +on the command line, this program will ask the kernel to make the repairs and +to perform the optimizations. +See the sections about optimizations and repairs for a list of optimizations +and repairs known to this program. +The kernel may not support repairing or optimizing the filesystem. +If this is the case, the filesystem must be unmounted and +.BR xfs_repair (8) +run on the filesystem to fix the problems. +.SH OPTIONS +.TP +.BI \-a " errors" +Abort if more than this many errors are found on the filesystem. +.TP +.B \-b +Run in background mode. +If the option is specified once, only run a single scrubbing thread at a +time. +If given more than once, an artificial delay of 100us is added to each +scrub call to reduce CPU overhead even further. +.TP +.BI \-C " fd" +This option causes xfs_scrub to write progress information to the +specified file description so that the progress of the filesystem check +can be monitored. +If the file description is a tty, a fancy progress bar is rendered. +Otherwise, a simple numeric status dump compatible with the +.B fsck -C +format is output. +.TP +.B \-e +Specifies what happens when errors are detected. +If +.IR shutdown +is given, the filesystem will be taken offline if errors are found. +If +.IR continue +is given, no action is taken if errors are found; this is the default +behavior. +.TP +.B \-k +Do not call TRIM on the free space. +.TP +.BI \-m " file" +Search this file for mounted filesystems instead of /etc/mtab. +.TP +.B \-n +Only check filesystem metadata. +Do not repair or optimize anything. +.TP +.BI \-T +Print timing and memory usage information for each phase. +.TP +.B \-v +Enable verbose mode, which prints periodic status updates. +.TP +.B \-V +Prints the version number and exits. +.TP +.B \-x +Read all file data extents to look for disk errors. +.B xfs_scrub +will issue O_DIRECT reads to the block device directly. +If the block device is a SCSI disk, it will instead issue READ VERIFY commands +directly to the disk. +If media errors are found, the error report will include the disk offset, in +bytes. +If the media errors affect a file, the report will also include the inode +number and file offset, in bytes. +These actions will confirm that all file data blocks can be read from storage. +.SH OPTIMIZATIONS +Optimizations supported by this program include, but are not limited to: +.IP \[bu] 2 +Instructing the underlying storage to discard unused extents via the +.B TRIM +ioctl. +.IP \[bu] +Updating secondary superblocks to match the primary superblock. +.IP \[bu] +Turning off shared block write checks for files that no longer share blocks. +.SH REPAIRS +Repairs are performed by calling into the kernel. +This limits the scope of repair activities to rebuilding primary data +structures from secondary data structures, or secondary structures from +primary structures. +The existence of secondary data structures may require features that can +only be turned on from +.BR mkfs.xfs (8). +If errors cannot be repaired, the filesystem must be +unmounted and +.BR xfs_repair (8) +run. +Repairs supported by the kernel include, but are not limited to: +.IP \[bu] 2 +Reconstructing extent allocation data. +.IP \[bu] +Rebuilding free space information. +.IP \[bu] +Rebuilding inode indexes. +.IP \[bu] +Fixing minor corruptions of inode records. +.IP \[bu] +Recalculating reference count information. +.IP \[bu] +Reconstructing reverse mapping data from primary extent allocation data. +.IP \[bu] +Scheduling a quotacheck for the next mount. +.PP +If corrupt metadata is successfully repaired, this program will log that +a repair has succeeded instead of a corruption report. +.SH EXIT CODE +The exit code returned by +.B xfs_scrub +is the sum of the following conditions: +.br +\ 0\ \-\ No errors +.br +\ 1\ \-\ File system errors left uncorrected +.br +\ 2\ \-\ File system optimizations possible +.br +\ 4\ \-\ Operational error +.br +\ 8\ \-\ Usage or syntax error +.br +.SH CAVEATS +.B xfs_scrub +is an immature utility! +Do not run this program unless you have backups of your data! +This program takes advantage of in-kernel scrubbing to verify a given +data structure with locks held and can keep the filesystem busy for a +long time. +The kernel must be new enough to support the SCRUB_METADATA ioctl. +.PP +If errors are found and cannot be repaired, the filesystem must be +unmounted and repaired. +.SH SEE ALSO +.BR xfs_repair (8). |