On 2/25/2020 9:53 AM, John Kennedy wrote:
On Tue, Feb 25, 2020 at 11:07:48AM +0000, Pete French wrote:I have often wondered if ZFS is more aggressive with discs, because until very recently any solid state drive I have used ZFS on broke very quicky. ...I've always wondered if ZFS (and other snapshotting file systems) would help kill SSD disks by locking up blocks longer than other filesystems might. For example, I've got snapshot-backups going back, say, a year then those blocks that haven't changed aren't going back into the pool to be rewritten (and perhaps favored because of low write-cycle count). As the disk fills up, the blocks that aren't locked up get reused more and more, leading to extra wear on them. Eventually one of those will get to the point of erroring out.Personally, I just size generously but that isn't always an option for everybody.
I have a ZFS RaidZ2 on SSDs that has been running for several /years /without any problems. The drives are Intel 730s, which Intel CLAIMS don't have power-loss protection but in fact appear to; not only do they have caps in them but in addition they pass a "pull the cord out of the wall and then check to see if the data is corrupted on restart" test on a repeated basis, which I did several times before trusting them.
BTW essentially all non-data-center SSDs fail that test and some fail it spectacularly (destroying the OS due to some of the in-flight data being comingled on an allocated block with something important; if the read/erase/write cycle interrupts you're cooked as the "other" data that was not being modified gets destroyed too!) -- the Intels are one of the very, very few that have passed it.
-- -- Karl Denninger /The Market-Ticker/ S/MIME Email accepted and preferred
smime.p7s
Description: S/MIME Cryptographic Signature
