On Thu, May 9, 2019 at 5:37 AM Miroslav Lachman <[email protected]> wrote:
>
> Dimitry Andric wrote on 2019/05/09 13:02:
> > On 9 May 2019, at 10:32, Miroslav Lachman <[email protected]> wrote:
>
> [...]
>
> >> Disks are OK, monitored by smartmontools. There is nothing odd, just the 
> >> long long scrubs. This machine was started with 4x 1TB (now 4x 4TB) and 
> >> scrub was slow with 1TB disks too. This machine - HP ML110 G8) was my 
> >> first machine with ZFS. If I remember it well it was FreeBSD 7.0, now 
> >> running 11.2. Scrub was / is always about one week. (I tried some sysctl 
> >> tuning without much gain)
> >
> > Unfortunately https://svnweb.freebsd.org/changeset/base/339034, which
> > greatly speeds up scrubs and resilvers, was not in 11.2 (since it was
> > cut at r334458).
> >
> > If you could update to a more recent snapshot, or try the upcoming 11.3
> > prereleases, you will hopefully see much shorter scrub times.
>
> Thank you. I will try 11-STABLE / 11.3-PRERELEASE soon and let you know
> about the difference.
>
> Kind regards
> Miroslav Lachman

On 11.3 and even much older releases, you can greatly speed up scrub
and resilver by tweaking some sysctls.  If you have spinning rust,
raise vfs.zfs.top_maxinflight so they'll do fewer seeks.  I used to
set it to 8192 on machines with 32GB of RAM.  Raising
vfs.zfs.resilver_min_time_ms to 5000 helps a little, too.

-Alan
_______________________________________________
[email protected] mailing list
https://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "[email protected]"

Reply via email to