[Linux-cluster] GFS performance

Treece, Britt Britt.Treece at savvis.net
Wed Jul 12 16:51:10 UTC 2006


Paul,

 

Does the GFS lock traffic have its own interface on each server and
segmented switch network?

 

What does the perl script do?

 

Regards,

 

Britt Treece

 

________________________________

From: linux-cluster-bounces at redhat.com
[mailto:linux-cluster-bounces at redhat.com] On Behalf Of Paul n McDowell
Sent: Wednesday, July 12, 2006 10:49 AM
To: linux-cluster at redhat.com
Subject: [Linux-cluster] GFS performance

 


Hi, 

Can anyone provide techniques or suggestions to improve GFS performance?


The problem we have is best summarized by the output of a perl script
that one of our frustrated developers has written: 

The script simply creates a file, then reads it, then removes it and
prints out the time it takes for each of these instructions to complete.
Sometimes it takes only a second to do all three, while sometimes it
takes as long as 15 seconds to do these 3 simple instructions.  I've run
the script on all of the five GFS file systems and see the same response
characteristics.  I've run the script when the systems and when they are
fairly quiet and still see the same issue. 


To summarize the environment: 

RH ES3 update 6 (GFS 6.0) 11 node cluster environment with 3 redundant
lock managers and five GFS file systems mounted on each participating
servers.  The GFS file systems range from 100GB to 1.5 TB. 

The storage array is an EMC CX700 attached to a dual redundant SAN
consisting four 2GB Brocade 3900 SAN switches.   

The HBA's in all servers are Qlogic qla2340's  Firmware version:
3.03.14, Driver version 7.07.00 

The servers are all HP DL585 64bit AMD opteron server class machines
each configured with between 8GB and 32GB of memory. 


........................................................................
........................................................................
........................................................................
............................. 

I've raised a support call with RedHat but according to their experts
our configuration seems already to be set for optimum performance. 

RedHat provide a utility to get and set tunable gfs file systems
parameters but there is next to no supporting documentation. 

So, is there anything I can do or am I missing something obvious that is
just plainly mis-configured? 

Shown below is the GFS configuration summary derived from lock_gulmd -C
and gfs_tool df for each file system. 

I'll be happy to supply any other information if it will help. 

Thanks to all in advance 

Paul McDowell 



lock_gulmd -C 

# hashed: 0x44164246 
cluster { 
 name = "cra_gfs" 
 lock_gulm { 
  heartbeat_rate = 15.000 
  allowed_misses = 3 
  coreport = 40040 
  new_connection_timeout = 15.000 
  # server cnt: 3 
  # servers = ["iclc1g.cra.applera.net", "iclc2g.cra.applera.net",
"ccf001g.cra.applera.net"] 
  servers = ["172.20.8.21", "172.20.8.22", "172.20.8.51"] 
  lt_partitions = 4 
  lt_base_port = 41040 
  lt_high_locks = 20971520 
  lt_drop_req_rate = 300 
  prealloc_locks = 5000000 
  prealloc_holders = 11000000 
  prealloc_lkrqs = 60 
  ltpx_port = 40042 
  

#gfs_tool df 


/crx: 
  SB lock proto = "lock_gulm" 
  SB lock table = "cra_gfs:cra_crx" 
  SB ondisk format = 1308 
  SB multihost format = 1401 
  Block size = 4096 
  Journals = 11 
  Resource Groups = 1988 
  Mounted lock proto = "lock_gulm" 
  Mounted lock table = "cra_gfs:cra_crx" 
  Mounted host data = "" 
  Journal number = 0 
  Lock module flags = async 
  Local flocks = FALSE 
  Local caching = FALSE 

  Type           Total          Used           Free           use%

 
------------------------------------------------------------------------

  inodes         933593         933593         0              100% 
  metadata       943899         121868         822031         13% 
  data           128274180      58546879       69727301       46% 


[root at iclc1g tmp]# gfs_tool df /crx/data 
/crx/data: 
  SB lock proto = "lock_gulm" 
  SB lock table = "cra_gfs:cra_crxdata" 
  SB ondisk format = 1308 
  SB multihost format = 1401 
  Block size = 4096 
  Journals = 11 
  Resource Groups = 5970 
  Mounted lock proto = "lock_gulm" 
  Mounted lock table = "cra_gfs:cra_crxdata" 
  Mounted host data = "" 
  Journal number = 0 
  Lock module flags = async 
  Local flocks = FALSE 
  Local caching = FALSE 

  Type           Total          Used           Free           use%

 
------------------------------------------------------------------------

  inodes         3296091        3296091        0              100% 
  metadata       2649271        616186         2033085        23% 
  data           385236382      310495360      74741022       81% 

[root at iclc1g tmp]# gfs_tool df /crx/home 
/crx/home: 
  SB lock proto = "lock_gulm" 
  SB lock table = "cra_gfs:cra_crxhome" 
  SB ondisk format = 1308 
  SB multihost format = 1401 
  Block size = 4096 
  Journals = 11 
  Resource Groups = 3978 
  Mounted lock proto = "lock_gulm" 
  Mounted lock table = "cra_gfs:cra_crxhome" 
  Mounted host data = "" 
  Journal number = 0 
  Lock module flags = async 
  Local flocks = FALSE 
  Local caching = FALSE 

  Type           Total          Used           Free           use%

 
------------------------------------------------------------------------

  inodes         3477487        3477487        0              100% 
  metadata       3162164        341627         2820537        11% 
  data           254032093      157709829      96322264       62% 

[root at iclc1g tmp]# gfs_tool df /usr/local 
/usr/local: 
  SB lock proto = "lock_gulm" 
  SB lock table = "cra_gfs:cra_usrlocal" 
  SB ondisk format = 1308 
  SB multihost format = 1401 
  Block size = 4096 
  Journals = 11 
  Resource Groups = 394 
  Mounted lock proto = "lock_gulm" 
  Mounted lock table = "cra_gfs:cra_usrlocal" 
  Mounted host data = "" 
  Journal number = 0 
  Lock module flags = async 
  Local flocks = FALSE 
  Local caching = FALSE 

  Type           Total          Used           Free           use%

 
------------------------------------------------------------------------

  inodes         765762         765762         0              100% 
  metadata       582989         22854          560135         4% 
  data           24393837       9477084        14916753       39% 

[root at iclc1g tmp]# gfs_tool df /data 
/data: 
  SB lock proto = "lock_gulm" 
  SB lock table = "cra_gfs:cra_GQ" 
  SB ondisk format = 1308 
  SB multihost format = 1401 
  Block size = 4096 
  Journals = 11 
  Resource Groups = 1298 
  Mounted lock proto = "lock_gulm" 
  Mounted lock table = "cra_gfs:cra_GQ" 
  Mounted host data = "" 
  Journal number = 0 
  Lock module flags = async 
  Local flocks = FALSE 
  Local caching = FALSE 

  Type           Total          Used           Free           use%

 
------------------------------------------------------------------------

  inodes         10026          10026          0              100% 
  metadata       282680         189037         93643          67% 
  data           103761726      94277221       9484505        91% 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/linux-cluster/attachments/20060712/1e69350a/attachment.htm>


More information about the Linux-cluster mailing list