[Linux-cluster] GFS RG size (and tuning)

[Jos Vos]

Hi,

The gfs_mkfs manual page (RHEL 5.0) says:

  If not  specified,  gfs_mkfs  will  choose the RG size based on the size
  of the file system: average size file systems will have 256 MB  RGs,
  and bigger file systems will have bigger RGs for better performance.

My 3 TB filesystems still seem to have 256 MB RG's (I don't know how to
see the RG size, but there are 11173 of them, so that seems to indicate
a size of 256 MB).  Is 3 TB considered to be "average size"? ;-)

Anyway, it is recommended trying to rebuild the fs's with "-r 2048" for
3 TB filesystems, each with between 1 and 2 million files on it?
Especially gfs_scand uses *huge* amounts of CPU time and doing df takes
a *very* long time....

Regards,

--
--    Jos Vos <jos at xos.nl>
--    X/OS Experts in Open Systems BV   |   Phone: +31 20 6938364
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