Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 4 Jan 2016 21:40:20 -0600
From:      Adam Vande More <amvandemore@gmail.com>
To:        Paul Kraus <paul@kraus-haus.org>
Cc:        FreeBSD Filesystems <freebsd-fs@freebsd.org>, "Mikhail T." <mi+thun@aldan.algebra.com>
Subject:   Re: NFS reads vs. writes
Message-ID:  <CA%2BtpaK06bbFat--1xYDnWnShNziV3z9F5X3kwiY1APQxB55G0Q@mail.gmail.com>
In-Reply-To: <D0AC7351-25DC-478C-981E-E32B1F5E353F@kraus-haus.org>
References:  <8291bb85-bd01-4c8c-80f7-2adcf9947366@email.android.com> <5688D3C1.90301@aldan.algebra.com> <495055121.147587416.1451871433217.JavaMail.zimbra@uoguelph.ca> <568A047B.1010000@aldan.algebra.com> <CAGtEZUD28UZDYyHtHtzXgys%2Brpv_37u4fotwR%2BqZLc1%2BtK0dwA@mail.gmail.com> <D0AC7351-25DC-478C-981E-E32B1F5E353F@kraus-haus.org>

next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jan 4, 2016 at 9:06 PM, Paul Kraus <paul@kraus-haus.org> wrote:

> I have a file server that I am going through the task of optimizing for
> NFS traffic (to store VM images). My first attempt, because I knew about
> the need for an SSD based SLOG for the ZIL was using a pair of Intel 535
> series SSD=E2=80=99s. The performance with the SLOG/ZIL on the SSD was _w=
orse_.
> Turns out that those SSD=E2=80=99s have poor small block (8 KB) random wr=
ite
> performance (not well advertised). So I asked for advice for choosing a
> _fast_ SSD on the OpenZFS list and had a number of people recommend the
> Intel DC-Sxxxx series of SSDs.
>
> Based on the very thorough data sheets, I am going with a pair of DC-S371=
0
> 200 GB SSDs. Once I get them in and configured I=E2=80=99ll post results.
>
> Note that my zpool consists of 5 top level vdevs each made up of a 3-way
> mirror. So I am striping writes across 5 columns. I am using 500 GB WD RE
> series drives leaving the ZIL on the primary vdevs was _faster_ than addi=
ng
> the consumer SSD as SLOG for NFS writes


Something like zeusram or ddrdrive is probably going to yield the most
preformant solution for zfs sync writes.



--=20
Adam



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CA%2BtpaK06bbFat--1xYDnWnShNziV3z9F5X3kwiY1APQxB55G0Q>