Date: Fri, 11 May 2007 13:55:46 -0600 From: Scott Long <scottl@samsco.org> To: David Wolfskill <david@catwhisker.org>, stable@freebsd.org Subject: Re: 6.2-R on Dell Poweredge 2950 with Dell PERC 5/i [mfi(4)] Message-ID: <4644CA42.3040706@samsco.org> In-Reply-To: <20070511191511.GX64542@bunrab.catwhisker.org> References: <20070510200211.GM64542@bunrab.catwhisker.org> <4643A739.3080601@samsco.org> <20070511191511.GX64542@bunrab.catwhisker.org>
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David Wolfskill wrote: > On Thu, May 10, 2007 at 05:14:01PM -0600, Scott Long wrote: >> ... >> Not sure that this impression is entirely accurate. The biggest problem >> with MFI machines is online RAID management. The storage driver itself >> matured very quickly and has been very reliable. > > Ah; good to know: thank you. > >>> Well, now a colleague is trying to run 6.2-R on one of these 2950s; dmesg >>> says the controller is: >>> >>> mfi0: <Dell PERC 5/i> mem 0xd80f0000-0xd80fffff,0xfc4e0000-0xfc4fffff irq >>> 78 at device 14.0 on pci2 >> ... >>> and the disks looks like: >>> >>> mfid0: <MFI Logical Disk> on mfi0 >>> mfid0: 418176MB (856424448 sectors) RAID volume '' is optimal >>> >> Looks A OK to me. > > Even better. :-) > >>> The intended production workload involves creation and deletion of >>> a large number of files rather rapidly. >> ... >> sysctl vfs.ffs.doasyncfree=0 might help. Running the syncer more >> frequently might also help, but I don't recall the sysctl node for >> that. > > OK; I've relayed your suggestion to my colleague, but haven't heard back > from her yet. > >> ... >> Very strange. No chance that it was due to files that were deleted but >> still referenced by open apps? > > I don't think so. She's deployed 13 other boxen over the last few years > with -- naturally! -- different hardware specs, but all running > essentailly the same application. > > The big question for her is whether or not the Dell 2950, as specified, > will do the job. > >> ... >> This sounds purely like a filesystem issue, not an MFI driver issue. > > Hmmm... I'll admit to knowing little about RAID configurations; is it > possible that some RAID configurations might exacerbate problems with > such a workload -- or that others might be more amenable to it? > If anything, a fast RAID controller will help reduce the lag that you get when the syncer does its periodic run. But beyond that, I can't think of anything that would cause problems. Scott
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