carmen wrote:
On Thu Jul 06, 2006 at 02:00:05PM -0400, Dan Easley wrote:
On 7/6/06, Pieter Palmers <pieterp@xxxxxxx> wrote:
Paul Winkler wrote:
On Thu, Jul 06, 2006 at 01:43:40PM +0200, Pieter Palmers wrote:
Modern harddisks use a lot of write caching on the controller to achieve
decent performance. So when power goes down when there is data in the
write cache, it is lost. The file system however 'thinks' that data has
been written correctly. This hence results in file system corruption.
Thanks much for this whole thread. It's added substance to what I
previously thought was just personal paranoia and suspicion.
I've been under the impression it's cheaper to buy used UPS's and buy
replacement batteries for them. Has anyone done this to good results?
im guessing 2 drives , synched nightly via rsync, or in a RAID configuration, is cheaper, and friendlier for the environment than huge/heavy UPS batteries. i guess i'd invest in that if the electricity infrastructure in my area was particularly bad. or in combination with daytime solar replenishing to run completely off-grid.
The RAID does *not* help against power failures. been there, done that.
rsync will do, but then you have to make sure that the outage does not
occur when running rsync. Anyway it lowers the chance that you'll have
problems.
soudns like overkill as a hedge against drive failure though. drives will fail.
UPS'es don't prevent mechanical drive failure, but they do prevent
'soft' bad sectors. My belief is that these are the most common.
I wouldn't think a 100€ UPS is more overkill than an extra 160G drive
(costing about the same) for RAID/rsync mirroring.
I've made up my mind about this: 'this UPS is to stay', but feel free
not to agree of course ;)
Pieter
