3.12.2. Displaying GFS Counters

3.12.2. 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 filesystem 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

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