4.13. Displaying Extended GFS Information and Statistics

You can use the gfs_tool command to gather a variety of details about GFS. This section describes typical use of the gfs_tool command for displaying space usage, statistics, and extended status.
The gfs_tool command provides additional action flags (options) not listed in this section. For more information about other gfs_tool flags, refer to the gfs_tool man page.

4.13.1. Displaying GFS Space Usage

You can use the df flag of the gfs_tool to display a space-usage summary of a given file system. The information is more detailed than a standard df.

Usage

gfs_tool df MountPoint
MountPoint
Specifies the file system to which the action applies.

Example

This example reports extended file system usage about file system /mnt/gfs.
[root@ask-07 ~]# gfs_tool df /mnt/gfs
/gfs:
  SB lock proto = "lock_dlm"
  SB lock table = "ask_cluster:mydata1"
  SB ondisk format = 1309
  SB multihost format = 1401
  Block size = 4096
  Journals = 8
  Resource Groups = 605
  Mounted lock proto = "lock_dlm"
  Mounted lock table = "ask_cluster:mydata1"
  Mounted host data = "jid=0:id=786433:first=1"
  Journal number = 0
  Lock module flags = 0
  Local flocks = FALSE
  Local caching = FALSE
  Oopses OK = FALSE

  Type           Total          Used           Free           use%
  ------------------------------------------------------------------------
  inodes         5              5              0              100%
  metadata       78             15             63             19%
  data           41924125       0              41924125       0%

4.13.2. Displaying GFS Counters

You can use the counters flag of the gfs_tool to display statistics about a file system. If the -c option is used, the gfs_tool command continues to run, displaying statistics once per second.

Note

The majority of the GFS counters reflect the internal operation of the GFS file system and are for development purposes only.
The gfs_tool counters command displays the following statistics.
locks
The number of gfs_glock structures that currently exist in gfs.
locks held
The number of existing gfs_glock structures that are not in the UNLOCKED state.
freeze count
A freeze count greater than 0 means the file system is frozen. A freeze count of 0 means the file system is not frozen. Each gfs_tool freeze command increments this count. Each gfs_tool unfreeze command decrements this count.
incore inodes
The number of gfs_inode structures that currently exist in gfs.
metadata buffers
The number of gfs_bufdata structures that currently exist in gfs.
unlinked inodes
The gfs_inoded daemon links deleted inodes to a global list and cleans them up every 15 seconds (a period that is tunable). This number is the list length. It is related to the number of gfs_unlinked structures currently in gfs.
quota IDs
The number of gfs_quota_data structures that currently exist in gfs.
incore log buffers
The number of buffers in in-memory journal log (incore log), before they are flushed to disk.
log space used
The the percentage of journal space used.
meta header cache entries
The number of gfs_meta_header_cache structures that currently exist in gfs.
glock dependencies
The number of gfs_depend structures that currently exist in gfs.
glocks on reclaim list
The number of glocks on the reclaim list.
log wraps
The number of times journal has wrapped around.
outstanding LM calls
obsolete
outstanding BIO calls
obsolete
fh2dentry misses
The number of times an NFS call could not find a dentry structure in the cache.
glocks reclaimed
The number of glocks which have been reclaimed.
glock dq calls
The number of glocks released since the file system was mounted.
glock prefetch calls
The number of glock prefetch calls.
lm_lock calls
The number of times the lock manager has been contacted to obtain a lock.
lm_unlock calls
The number of times the lock manager has been contacted to release a lock.
lm callbacks
The number of times the lock manager has been contacted to change a lock state.
address operations
The number of address space call operations (readpage, writepage, directIO, prepare_write, and commit_write)
dentry operations
The number of times a seek operation has been performed on the vfs dentry structure.
export operations
The number of times a seek operation has been performed on the nfs dentry structure.
file operations
The number of file operations that have been invoked (read, write, seek, etc).
inode operations
The number of inode operations that have been invoked (create, delete, symlink, etc.).
super operations
The number of super block operations.
vm operations
The number of times the mmap function has been called. mmap call count
block I/O reads
obsolete
block I/O writes
obsolete

Usage

gfs_tool counters MountPoint
MountPoint
Specifies the file system to which the action applies.

Example

This example reports statistics about the file system mounted at /mnt/gfs.
[root@tng3-1 gfs]# gfs_tool counters /mnt/gfs

                                  locks 165
                             locks held 133
                           freeze count 0
                          incore inodes 34
                       metadata buffers 5
                        unlinked inodes 0
                              quota IDs 0
                     incore log buffers 0
                         log space used 0.05%
              meta header cache entries 5
                     glock dependencies 5
                 glocks on reclaim list 0
                              log wraps 0
                   outstanding LM calls 0
                  outstanding BIO calls 0
                       fh2dentry misses 0
                       glocks reclaimed 345
                         glock nq calls 11632
                         glock dq calls 11596
                   glock prefetch calls 84
                          lm_lock calls 545
                        lm_unlock calls 237
                           lm callbacks 782
                     address operations 1075
                      dentry operations 374
                      export operations 0
                        file operations 1428
                       inode operations 1451
                       super operations 21239
                          vm operations 0
                        block I/O reads 0
                       block I/O writes 0

4.13.3. Displaying Extended Status

You can use the stat flag of the gfs_tool to display extended status information about a GFS file.

Note

The information that the gfs_tool stat command displays reflects internal file system information. This information is intended for development purposes only.

Usage

gfs_tool stat File
File
Specifies the file from which to get information.

Example

This example reports extended file status about file /gfs/datafile.
[root@tng3-1 gfs]# gfs_tool stat /gfs/datafile
  mh_magic = 0x01161970
  mh_type = 4
  mh_generation = 3
  mh_format = 400
  mh_incarn = 1
  no_formal_ino = 66
  no_addr = 66
  di_mode = 0600
  di_uid = 0
  di_gid = 0
  di_nlink = 1
  di_size = 503156
  di_blocks = 124
  di_atime = 1207672023
  di_mtime = 1207672023
  di_ctime = 1207672023
  di_major = 0
  di_minor = 0
  di_rgrp = 17
  di_goal_rgrp = 17
  di_goal_dblk = 371
  di_goal_mblk = 44
  di_flags = 0x00000000
  di_payload_format = 0
  di_type = 1
  di_height = 1
  di_incarn = 0
  di_pad = 0
  di_depth = 0
  di_entries = 0
  no_formal_ino = 0
  no_addr = 0
  di_eattr = 0
  di_reserved =
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 
00 00 00 00 00 00 00 00