On Tue, Nov 30, 2010 at 3:21 PM, Brad Tilley <b...@16systems.com> wrote: > Kevin Chadwick wrote: > >> I almost completely agree, but also disagree and yes I'd say it's not >> worth getting into again. I would have to check the latest developments >> as I can imagine an algorithm which solved the problem during idle >> periods or didn't use it's full capacity but currently I don't agree >> fully with "huge amounts of data". The problem was reduced immensely by >> spreading writes across all free sectors rather than sequentially but I >> believe? the problem re-appears on a busy nearly full disk. I would also >> hope/imagine the only affect would be getting bad sectors in that area >> but I haven't looked into it very far as I currently have no need to >> and so maybe I should shut up untill I do. However, I for one will not >> be treating SSDs like HDDs in all applications of disks untill after I >> learn more. > > One thing you might consider... buy a SSD and do some testing. Attach it > to an OpenBSD box, put a file system on it, then write a script similar > to this to repeatedly fill and empty the file system: > > while : > do > dd if=/dev/arandom of=big_un.bin bs=64k > sync > sleep 1 > rm -P big_un.bin > done > > Let that run for a few years and see how long the disk actually lasts. > You could put up a website with live results. You'd become famous too... > especially if you hit the decade mark and the thing still works :) > > Also, I just noticed that the high-end Intel SSDs claim 2,000,000 hours > MTBF. I wonder why they market that number and then say "3 year > warranty". There's only roughly 26,280 hours in a three year period. > > Brad
MTBF numbers are typically cumulative, i.e. for the population of devices as a whole. If you had 2,000,000 Intel SSDs, you could expect (statistically) for one of them to fail every hour. Paul. -- ------------------------------ Paul D. Ouderkirk Senior UNIX System Administrator p...@ouderkirk.ca ------------------------------ laughing, in the mechanism -- William Gibson
