[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: ZFS performance (was: Re: deduplicating file systems: VDO withDebian?)



On Fri, Nov 11, 2022 at 12:53:21PM -0500, Jeffrey Walton wrote:
> On Fri, Nov 11, 2022 at 2:01 AM <tomas@tuxteam.de> wrote:
> >
> > On Fri, Nov 11, 2022 at 07:15:07AM +0100, hw wrote:
> > > On Thu, 2022-11-10 at 23:05 -0500, Michael Stone wrote:
> >... Here's a report
> > by folks who do lots of HDDs and SDDs:
> >
> >   https://www.backblaze.com/blog/backblaze-hard-drive-stats-q1-2021/
> >
> > The gist, for disks playing similar roles (they don't use yet SSDs for bulk
> > storage, because of the costs): 2/1518 failures for SSDs, 44/1669 for HDDs.
> 
> Forgive my ignorance... Isn't Mean Time Before Failure (MTFB) the
> interesting statistic?

I think what hede was hinting at was that early SSDs had a (pretty)
limited number of write cycles per "block" [1] before failure; they had
(and have) extra blocks to substitute broken ones and do a fair amount
of "wear leveling behind the scenes. So it made more sense to measure
failures along the "TB written" axis than along the time axis.

Cheers

[1] In a very sloppy sense: those beasts have big write units, 256K and
up.

-- 
t

Attachment: signature.asc
Description: PGP signature


Reply to: