Date: Wed, 03 Feb 2010 04:15:06 -0600 From: "James R. Van Artsdalen" <james-freebsd-fs2@jrv.org> To: Dan Naumov <dan.naumov@gmail.com> Cc: freebsd-fs@freebsd.org, FreeBSD-STABLE Mailing List <freebsd-stable@freebsd.org>, freebsd-questions@freebsd.org Subject: Re: 8.0-RELEASE/amd64 - full ZFS install - low read and write disk performance Message-ID: <4B694CAA.60703@jrv.org> In-Reply-To: <cf9b1ee01001240836r56adb773yc593600273941d83@mail.gmail.com> References: <cf9b1ee01001240836r56adb773yc593600273941d83@mail.gmail.com>
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Dan Naumov wrote:
> [jago@atombsd ~]$ dd if=/dev/zero of=/home/jago/test2 bs=1M count=4096
> 4096+0 records in
> 4096+0 records out
> 4294967296 bytes transferred in 143.878615 secs (29851325 bytes/sec)
>
> This works out to 1GB in 36,2 seconds / 28,2mb/s in the first test and
> 4GB in 143.8 seconds / 28,4mb/s
For the record, better results can be seen. In my test I put 3 Seagate
Barracuda XT drives in a port multiplier and connected that to one port
of a PCIe 3124 card.
The MIRROR case is at about the I/O bandwidth limit of those drives.
[root@kraken ~]# zpool create tmpx ada{2,3,4}
[root@kraken ~]# dd if=/dev/zero of=/tmpx/test2 bs=1M count=4096
4096+0 records in
4096+0 records out
4294967296 bytes transferred in 20.892818 secs (205571470 bytes/sec)
[root@kraken ~]# zpool destroy tmpx
[root@kraken ~]# zpool create tmpx mirror ada{2,3}
[root@kraken ~]# dd if=/dev/zero of=/tmpx/test2 bs=1M count=4096
4096+0 records in
4096+0 records out
4294967296 bytes transferred in 36.432818 secs (117887321 bytes/sec)
[root@kraken ~]#
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