On Sun, Nov 28, 2010 at 5:43 PM, Mikael Abrahamsson <swmike@xxxxxxxxx> wrote: > What about data reliability? I'd recommend doing two RAID6:es out of the > drives you have and using them as PVs, one VG, and don't stripe them at all. > > <http://www.zdnet.com/blog/storage/why-raid-5-stops-working-in-2009/162> > applies to large drives even in RAID1. > > -- > Mikael Abrahamsson Mikael, I personally use "data availability" (my top priority listed) as inclusive of what you most likely mean by data reliability. I hadn't considered RAID6, as my understanding has been that it's usually implemented by specialized "enterprise-level" hardware, as opposed to my "consumer level" stuff, and much larger sets of disks than what I'm working with. Although performance isn't such a big issue for me, my (several generations old now) CPU will already be handling all the disk I/O discussed - plus the filer's going to be serving out a yet-to-be-determined number of iSCSI LUNs, so I'm willing to trade off space penalty for the performance and (even more important) the simplicity of RAID1 or RAID10. Regarding the possibility (IMO slim) of the primary drive failing during a straight-mirror rebuild, the first (smaller) RAID set is being regularly backed up to the larger one, and I'm even trying to build off-site disk rotation into my planning (we can't afford tapes). Next step up will be "full-server" mirroring via drdb/heartbeat to an offsite location, but we're not quite there yet. So I appreciate your "even better" suggestion, but do you have anything to say about the relative merits of the two alternatives I put forward? Thanks, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
