On Jun 3, 2010, at 10:33 AM, Ketan wrote:
> We are having a server running zfs root with 64G RAM and the system has 3
> zones running oracle fusion app and zfs cache is using 40G memory as per
> kstat zfs:0:arcstats:size. and system shows only 5G of memory is free rest is
> taken by kernel and 2 remaining zones.
> Now my problem is that fusion guys are getting not enough memory message
> while starting their application due to top and vmstat shows 5G as free
> memory. But i read ZFS cache releases memory as required by the application
> so why fusion application is not starting up.
ZFS will release the memory, but sometimes this can take a moment
and in the meantime, applications which are not written to retry allocations
are likely to bail out.
> Is there some we can do to decrease the ARC Cache usage on the fly without
> rebooting the global zone ?
This is a case where limiting the ARC size can be useful. For more information
see the ZFS Evil Tuning Guide
ZFS and NexentaStor training, Rotterdam, July 13-15, 2010
zfs-discuss mailing list