[Linux-cluster] GFS Tuning - it's just slow, to slow for production

Alan A alan.zg at gmail.com
Thu Mar 4 15:12:03 UTC 2010


Hello all - GFS2 is what we have deployed. It is fiber channel
connection/HBA to HP XP SAN.

*What workload are you tuning for? The chances are that you'll do a lot
better by adjusting the way in which the application(s) use the
filesystem rather than tweeking any specific tuning parameters. What
mount parameters are you using?*

>From /etc/fstab:
/dev/mapper/vg_acct10-lv_acct10 /acct10 gfs
rw,hostdata=jid=0:id=589826:first=1  0 0


We decided to delay production (no one is using GFS right now) but here are
the stats for GFS mount:

[root at fenclxmrcati11 ~]# gfs_tool counters /acct10

                                  locks 4206
                             locks held 2046
                           freeze count 0
                          incore inodes 2003
                       metadata buffers 84
                        unlinked inodes 0
                              quota IDs 0
                     incore log buffers 0
                         log space used 0.10%
              meta header cache entries 0
                     glock dependencies 0
                 glocks on reclaim list 0
                              log wraps 3
                   outstanding LM calls 0
                  outstanding BIO calls 0
                       fh2dentry misses 0
                       glocks reclaimed 154841
                         glock nq calls 15604058
                         glock dq calls 15600149
                   glock prefetch calls 3684
                          lm_lock calls 155504
                        lm_unlock calls 113531
                           lm callbacks 290967
                     address operations 22796796
                      dentry operations 1532231
                      export operations 0
                        file operations 16918046
                       inode operations 2190281
                       super operations 10224698
                          vm operations 201974
                        block I/O reads 0
                       block I/O writes 0
[root at fenclxmrcati11 ~]# gfs_tool stat /acct10
  mh_magic = 0x01161970
  mh_type = 4
  mh_generation = 63
  mh_format = 400
  mh_incarn = 0
  no_formal_ino = 26
  no_addr = 26
  di_mode = 0775
  di_uid = 500
  di_gid = 500
  di_nlink = 4
  di_size = 3864
  di_blocks = 1
  di_atime = 1267660812
  di_mtime = 1265728936
  di_ctime = 1266338341
  di_major = 0
  di_minor = 0
  di_rgrp = 0
  di_goal_rgrp = 0
  di_goal_dblk = 0
  di_goal_mblk = 0
  di_flags = 0x00000001
  di_payload_format = 1200
  di_type = 2
  di_height = 0
  di_incarn = 0
  di_pad = 0
  di_depth = 0
  di_entries = 4
  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

Flags:
  jdata
[root at fenclxmrcati11 ~]# gfs_tool gettune /acct10
ilimit1 = 100
ilimit1_tries = 3
ilimit1_min = 1
ilimit2 = 500
ilimit2_tries = 10
ilimit2_min = 3
demote_secs = 300
incore_log_blocks = 1024
jindex_refresh_secs = 60
depend_secs = 60
scand_secs = 5
recoverd_secs = 60
logd_secs = 1
quotad_secs = 5
inoded_secs = 15
glock_purge = 0
quota_simul_sync = 64
quota_warn_period = 10
atime_quantum = 3600
quota_quantum = 60
quota_scale = 1.0000   (1, 1)
quota_enforce = 1
quota_account = 1
new_files_jdata = 0
new_files_directio = 0
max_atomic_write = 4194304
max_readahead = 262144
lockdump_size = 131072
stall_secs = 600
complain_secs = 10
reclaim_limit = 5000
entries_per_readdir = 32
prefetch_secs = 10
statfs_slots = 64
max_mhc = 10000
greedy_default = 100
greedy_quantum = 25
greedy_max = 250
rgrp_try_threshold = 100
statfs_fast = 0









On Thu, Mar 4, 2010 at 8:59 AM, Carlos Maiolino <cmaiolino at redhat.com>wrote:

> On Thu, Mar 04, 2010 at 08:33:28AM -0600, Alan A wrote:
> > We are trying to deploy GFS in production, and are experiencing major
> > performance issues. What parameters in GFS settune can be changed to
> > increase I/O, to better tune performance? Application we run utilizes a
> lot
> > of I/O, please advise.
> >
> > We experience OK performance when starting, but as things ramp up and we
> get
> > few processes going GFS slows dramatically.
> >
> > --
> > Alan A.
>
> > --
> > Linux-cluster mailing list
> > Linux-cluster at redhat.com
> > https://www.redhat.com/mailman/listinfo/linux-cluster
>
>
> Hi Alan,
>
> Are you using GFS1 or GFS2 ?
>
> If you are using GFS1, try to use GFS2, GFS1 will be deprecated and GFS2
> has a lot of "auto-tuning" parameters as default and the performance is
> better as well.
> So, try to look at this document:
>
>
> http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5.4/html/Global_File_System_2/s1-manage-atimeconf.html
>
> see ya
>
> --
> ---
>
> Best Regards
>
> Carlos Eduardo Maiolino
>
> --
> Linux-cluster mailing list
> Linux-cluster at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-cluster
>



-- 
Alan A.
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