Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 9 May 2019 06:50:10 -0600
From:      Alan Somers <asomers@freebsd.org>
To:        Miroslav Lachman <000.fbsd@quip.cz>
Cc:        Dimitry Andric <dim@freebsd.org>,  FreeBSD-STABLE Mailing List <freebsd-stable@freebsd.org>
Subject:   Re: ZFS...
Message-ID:  <CAOtMX2ip_G0afh_4AaYcQt4=zX4qkCTfs0qb66DpCgcALZXS5g@mail.gmail.com>
In-Reply-To: <5de7f3d3-b34c-0382-b7d4-b7e38339649b@quip.cz>
References:  <30506b3d-64fb-b327-94ae-d9da522f3a48@sorbs.net> <CAGMYy3tYqvrKgk2c==WTwrH03uTN1xQifPRNxXccMsRE1spaRA@mail.gmail.com> <5ED8BADE-7B2C-4B73-93BC-70739911C5E3@sorbs.net> <d0118f7e-7cfc-8bf1-308c-823bce088039@denninger.net> <2e4941bf-999a-7f16-f4fe-1a520f2187c0@sorbs.net> <20190430102024.E84286@mulder.mintsol.com> <41FA461B-40AE-4D34-B280-214B5C5868B5@punkt.de> <20190506080804.Y87441@mulder.mintsol.com> <08E46EBF-154F-4670-B411-482DCE6F395D@sorbs.net> <33D7EFC4-5C15-4FE0-970B-E6034EF80BEF@gromit.dlib.vt.edu> <A535026E-F9F6-4BBA-8287-87EFD02CF207@sorbs.net> <a82bfabe-a8c3-fd9a-55ec-52530d4eafff@denninger.net> <a1b78a63-0ef1-af51-4e33-a9a97a257c8b@sorbs.net> <CAMPTd_A7RYJ12pFyY4TzbXct82kWfr1hcEkSpDg7bjP25xjJGA@mail.gmail.com> <d91cf5@sorbs.net> <7D18A234-E7BF-4855-BD51-4AE2253DB1E4@sorbs.net> <E68600B3-F856-4909-AB6E-BDFCD8AAAB43@punkt.de> <805ee7f1-83f6-c59e-8107-4851ca9fce6e@quip.cz> <E980141F-48D9-4870-8FE1-9A5610F12826@FreeBSD.org> <5de7f3d3-b34c-0382-b7d4-b7e38339649b@quip.cz>

next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, May 9, 2019 at 5:37 AM Miroslav Lachman <000.fbsd@quip.cz> wrote:
>
> Dimitry Andric wrote on 2019/05/09 13:02:
> > On 9 May 2019, at 10:32, Miroslav Lachman <000.fbsd@quip.cz> wrote:
>
> [...]
>
> >> Disks are OK, monitored by smartmontools. There is nothing odd, just t=
he 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 witho=
ut 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



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CAOtMX2ip_G0afh_4AaYcQt4=zX4qkCTfs0qb66DpCgcALZXS5g>