filesystem currently mounted on that node, or for the filesystem
that contains
.I path
-if given. It displaying current usage and totals for each MDT and
+if given. It displays the current usage and totals for each MDT and
OST separately, as well as a per-filesystem summary that matches
.BR df (1)
output for each filesystem.
+.PP
+By default
+.B lfs df
+reports the
+.I space
+usage of the OSTs (the MDT space usage is shown only for reference). With
+.B -i
+it reports the
+.I inode
+(object) usage for each target and in the summary. For ZFS-backed
+targets, the
+.B IUsed
+count accurately reflects the number of in-use objects on each target,
+but the
+.B Inodes
+total and
+.B Free
+inode counts are
+.I estimated
+based on the current average (mean) space used per object on each target,
+and may fluctuate over time to reflect the current usage pattern of
+the target. The estimate becomes more accurate as the target becomes
+more full, assuming the usage pattern is consistent.
+.PP
+.B lfs df
+may also report additional target status as the last column in the
+display, if there are issues with that target. States include:
+.RS 0.3i
+.TP
+.B D: degraded
+The target has a failed drive in the RAID device, or is undergoing
+RAID reconstruction. This state is marked on the server automatically
+for ZFS targets via
+.BR zed (8),
+or a (user-supplied) script that monitors the target device and sets
+.B lctl set_param obdfilter.\fI<target>\fB.degraded=1
+on the OST. This target will be avoided for new allocations, but
+will still be used for existing files located there or if there are
+not enough non-degraded OSTs to make up a widely-striped file.
+.TP
+.B R: read-only
+The target filesystem is marked read-only due to filesystem
+corruption detected by ldiskfs or ZFS. No modifications are
+allowed on this OST, and it needs to have
+.BR e2fsck (8)
+or
+.BR zpool (8) " scrub"
+run to repair the underlying filesystem.
+.TP
+.B S: out-of-space
+The target filesystem has less than the minimum required free space and
+will not be used for new object allocations until it has more free space.
+.TP
+.B I: out-of-inodes
+The target filesystem has less than the minimum required free inodes and
+will not be used for new object allocations until it has more free inodes.
+.RE
.SH OPTIONS
The various options supported by
.B lfs df
.TP
.BR -i ", " --inodes
Print information about the inode usage and totals for the MDTs and
-OSTs rather than space usage.
+OSTs rather than space usage. Note that the
+.B Inodes
+total,
+.BR IUsed ,
+and
+.B IFree
+counts typically reflect the
+.I sum
+of values from the MDTs. If the total number of objects available
+on the OSTs is smaller (factoring in the filesystem default
+.BR stripe_count ,
+as one OST object is used for each stripe in a file)
+then the reported
+.B Inodes
+and
+.B IFree
+values will be reduced to reflect the
+.I minimum
+number of files that could potentially be created with the default
+stripe count. The actual total number of files that can be created
+may be different.
.TP
.BR -l ", " --lazy
Do not attempt to contact any OST or MDT not currently connected to
the client. This avoids blocking the
.B lfs df
-output if an OST is down, and only returns the space on the OSTs that
-can currently be accessed.
+output if a target is offline or unreachable, and only returns the
+space on OSTs that can currently be accessed.
.TP
-.BR -p ", " --pool=\fR[\fIfsname\fR.]\fIpool
-Show only OSTs that are in the specified
+.BR -p ", " --pool= [ \fIfsname\fR .] \fIpool\fR
+Limit the usage to report only MDTs and OSTs that are in the specified
.IR pool .
If multiple filesystems are mounted, list OSTs in
.I pool
Lists space usage per OST and MDT for the
.B testfs
filesystem in human readable format.
+.PP
+.RS 0.75i
+UUID bytes Used Avail Use% Mounted on
+.br
+testfs-MDT0000_UUID 13.0G 1.2G 11.0G 10% /testfs[MDT:0]
+.br
+testfs-OST0000_UUID 3.6T 2.9T 585.7G 84% /testfs[OST:0]
+.br
+testfs-OST0001_UUID 3.6T 3.1T 472.5G 87% /testfs[OST:1] D
+.br
+testfs-OST0002_UUID 3.6T 3.0T 570.3G 84% /testfs[OST:2] DR
+.br
+OST0003 : inactive device
+.br
+testfs-OST0006_UUID 5.4T 4.9T 417.8G 92% /testfs[OST:3]
+.br
+
+filesystem_summary: 16.2T 13.8T 2.0T 88% /testfs
+.br
+.RE
+.PP
+The above example output shows that
+.B OST0003
+is currently temporarily inactive or offline, while
+.B OST0004
+and
+.B OST0005
+are not shown at all, either because they are marked permanently offline
+by the administrator (via
+.BR "lctl set_param -P osc.testfs-OST000[45].active=0" )
+or they were never added to the filesystem. The
+.B testfs-OST0001
+and
+.B testfs-OST0002
+targets are currently marked
+.B degraded
+(perhaps they both share the same underlying storage controller),
+while
+.B testfs-OST0002
+is also marked
+.B read-only
+after detecting non-recoverable corruption in the filesystem.
.TP
.B $ lfs df -i
List inode usage per OST and MDT for all mounted Lustre filesystems.
+.RS 0.75i
+UUID Inodes IUsed IFree IUse% Mounted on
+.br
+testfs-MDT0000_UUID 932160 884609 47551 95% /testfs[MDT:0]
+.br
+testfs-OST0000_UUID 267456 179649 87807 67% /testfs[OST:0]
+.br
+testfs-OST0001_UUID 268864 173466 95398 64% /testfs[OST:1] D
+.br
+testfs-OST0002_UUID 267456 169575 97881 63% /testfs[OST:2] DR
+.br
+OST0003 : inactive device
+.br
+testfs-OST0006_UUID 426144 377448 48696 88% /testfs[OST:3]
+.br
+
+filesystem_summary: 932160 884609 47551 95% /testfs
+.br
+.RE
.TP
.B $ lfs df --pool ssd /mnt/testfs
List space usage for only the
git://git.whamcloud.com / fs / lustre-release.git / blobdiff