Hello Erik, Wednesday, June 28, 2006, 6:32:38 PM, you wrote:
ET> Robert - ET> I would definitely like to see the difference between read on HW RAID5 ET> vs read on RAIDZ. Naturally, one of the big concerns I would have is ET> how much RAM is needed to avoid any cache starvation on the ZFS ET> machine. I'd discount the NVRAM on the RAID controller, since I'd ET> assume that it would be dedicated to write acceleration, and not for ET> read. My big problem right now is that I only have an old A3500FC to do ET> testing on, as all my other HW RAID controllers are IBM ServerRAIDs, for ET> which the Solaris driver isn't really the best. I belive the problem here was mostly due to 64kB read from each disk in raid-z while dataset was many TBs of data with small random reads from many threads (nfsd). It meant that during peak hours I wasn't probably far from saturating fc links (there was over 200MB read throughout sometime) while nfsd was actually reading someting like 10x less. I belive that most of that "cached" data weren't used. -- Best regards, Robert mailto:[EMAIL PROTECTED] http://milek.blogspot.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
