[Linux-cluster] GFS: fh2dentry misses

["Chad Slater" <chad slater clickfox com>]

While troubleshooting some GFS performance issues, I came across this when viewing the counters:

 

fh2dentry misses 292928

 

What is fh2dentry misses?

 

Here are my counters after the server had been up about 30 minutes.  Server1 is primary, server2 is secondary, and they export a 1.5TB GFS file system and a 1TB GFS file system via NFS.

 

server1# gfs_tool  counters /<path>

locks 1381450
locks held 717600
incore inodes 687837
metadata buffers 0
unlinked inodes 0
quota IDs 0
incore log buffers 0
log space used 0.05%
meta header cache entries 0
glock dependencies 0
glocks on reclaim list 0
log wraps 1
outstanding LM calls 0
outstanding BIO calls 3
fh2dentry misses 292928
glocks reclaimed 641232
glock nq calls 17182855
glock dq calls 16460254
glock prefetch calls 1003991
lm_lock calls 2384352
lm_unlock calls 1615283
lm callbacks 4009688
address operations 835770
dentry operations 121681
export operations 3157423
file operations 715530
inode operations 11415856
super operations 3533953
vm operations 0
block I/O reads 1263007
block I/O writes 168759

server2# gfs_tool counters /<path>

locks 5787
locks held 32
incore inodes 5
metadata buffers 0
unlinked inodes 0
quota IDs 0
incore log buffers 0
log space used 0.00%
meta header cache entries 0
glock dependencies 0
glocks on reclaim list 0
log wraps 0
outstanding LM calls 0
outstanding BIO calls 0
fh2dentry misses 0
glocks reclaimed 1217379
glock nq calls 1230292
glock dq calls 1230285
glock prefetch calls 0
lm_lock calls 1223696
lm_unlock calls 1221535
lm callbacks 2449408
address operations 0
dentry operations 0
export operations 0
file operations 3
inode operations 430
super operations 5052
vm operations 0
block I/O reads 10811
block I/O writes 4

*Pardon the non-plaintext format.