On Mon, 21 Sep 2009 16:30:25 EDT erik quanstrom <quans...@quanstro.net> wrote: > > > i think the lesson here is don't by cheep drives; if you > > > have enterprise drives at 1e-15 error rate, the fail rate > > > will be 0.8%. of course if you don't have a raid, the fail > > > rate is 100%. > > > > > > if that's not acceptable, then use raid 6. > > > > Hopefully Raid 6 or zfs's raidz2 works well enough with cheap > > drives! > > don't hope. do the calculations. or simulate it.
The "hopefully" part was due to power supplies, fans, mobos. I can't get hold of their reliability data (not that I have tried very hard). Ignoring that, raidz2 (+ venti) is good enough for my use. > this is a pain in the neck as it's a function of ber, > mtbf, rebuild window and number of drives. > > i found that not having a hot spare can increase > your chances of a double failure by an order of > magnitude. the birthday paradox never ceases to > amaze. I plan to replace one disk every 6 to 9 months or so. In a 3+2 raidz2 array disks will be swapped out in 2.5 to 3.75 years in the worst case. What I haven't found is a decent, no frills, sata/e-sata enclosure for a home system.
