On Fri, Jan 21, 2005 at 11:09:01AM -0800, Don Lewis wrote: > On 21 Jan, Erik Trulsson wrote: > > On Fri, Jan 21, 2005 at 08:31:06AM -0800, Kevin Oberman wrote: > > >> For servers that lack solid backup power (not a 10 minute > >> UPS), I would probably turn it off. But for most systems it is probably > >> worth the risks. > > > > A 10 minute UPS should be plenty for that purpose. All that is needed > > to protect against the risks of write-caching is for the server to be > > able to make an orderly shutdown, which should not take more than a > > couple of minutes. (If you need constant uptime, you need better power > > backup, but that is a different issue.) > > I guess that you haven't had as many UPS failures as I have had. The > usual problem is sudden battery and unexpected battery death which > brings the UPS runtime close to zero. > > The UPSes definitely help with the short hits to the power, but for > anything important I pay the outrageously high premium for SCSI disks > and turn off write caching. At least SCSI has working tagged command > queuing that when used with softupdates avoids the performance hit > caused by turning off write caching, at least for most workloads.
Does SATA support an equivalent to tagged queuing? -- Jim C. Nasby, Database Consultant [EMAIL PROTECTED] Give your computer some brain candy! www.distributed.net Team #1828 Windows: "Where do you want to go today?" Linux: "Where do you want to go tomorrow?" FreeBSD: "Are you guys coming, or what?" _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
