Albert Chin wrote: > On Thu, Jul 03, 2008 at 01:43:36PM +0300, Mertol Ozyoney wrote: > >> You are right that J series do not have nvram onboard. However most Jbods >> like HPS's MSA series have some nvram. >> The idea behind not using nvram on the Jbod's is >> >> -) There is no use to add limited ram to a JBOD as disks already have a lot >> of cache. >> -) It's easy to design a redundant Jbod without nvram. If you have nvram and >> need redundancy you need to design more complex HW and more complex firmware >> -) Bateries are the first thing to fail >> -) Servers already have too much ram >> > > Well, if the server attached to the J series is doing ZFS/NFS, > performance will increase with zfs:zfs_nocacheflush=1. But, without > battery-backed NVRAM, this really isn't "safe". So, for this usage case, > unless the server has battery-backed NVRAM, I don't see how the J series > is good for ZFS/NFS usage. > >
The zfs_nocacheflush problem should be mostly gone as the fix was implemented in b74. We really expect that this recommendation will disappear, except in its viral form. http://bugs.opensolaris.org/view_bug.do?bug_id=6462690 You really don't want to set this when using common, magnetic disks in a JBOD (J-series means JBOD) because there is no non-volatile cache. For good ZFS+NFS performance under attribute-creating-intensive loads using JBODs, we recommend using a slog. -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
