From: Stan Hoeppner <stan@hardwarefreak.com>
To: John Robinson <john.robinson@anonymous.org.uk>
Cc: Jack Wang <jack.wang.usish@gmail.com>, linux-raid@vger.kernel.org
Subject: Re: RAID5 created by 8 disks works with xfs
Date: Mon, 02 Apr 2012 15:41:27 -0500 [thread overview]
Message-ID: <4F7A0EF7.5010804@hardwarefreak.com> (raw)
In-Reply-To: <4F797F46.10600@anonymous.org.uk>
On 4/2/2012 5:28 AM, John Robinson wrote:
> My fantasy configuration in your 16-drive chassis would be 2 6-drive
> RAID6s, striped together in RAID0, with an SSD cache over the top built
> from two SSDs in RAID10 (or if I was feeling really paranoid, 3 SSDs in
> RAID10,n3), with the remaining slot containing a hot spare for the RAID6s.
This advice is not sound. The introductory "My fantasy" tends to put an
exclamation point on this fact. This configuration is completely
unsuitable for the workload described.
I already described the most optimal configuration for this workload,
given the OP's current hardware, including all the commands to build it.
The staged SSD idea has merit, as well as the SSD write cache idea. If
going this route, two SLC SSDs should simply be mirrored. Using 3 of
them or a RAID 1E variant on two of them is silly.
--
Stan
next prev parent reply other threads:[~2012-04-02 20:41 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-31 1:22 RAID5 created by 8 disks works with xfs daobang wang
2012-03-31 7:59 ` Mathias Burén
2012-03-31 20:09 ` Stan Hoeppner
2012-04-01 1:16 ` daobang wang
2012-04-01 2:05 ` daobang wang
2012-04-01 5:13 ` Stan Hoeppner
2012-04-01 3:51 ` Stan Hoeppner
2012-04-01 5:12 ` daobang wang
2012-04-01 5:40 ` Stan Hoeppner
2012-04-01 5:59 ` daobang wang
2012-04-01 6:20 ` daobang wang
2012-04-01 7:08 ` Marcus Sorensen
2012-04-02 3:47 ` Stan Hoeppner
2012-04-05 0:48 ` daobang wang
[not found] ` <CACwgYDOtCoVF-p+KKqPYxHhA4vWF78Ueecx9hcVWLoyxFWzV9Q@mail.gmail.com>
2012-04-05 21:01 ` Stan Hoeppner
2012-04-06 0:25 ` daobang wang
2012-04-06 2:33 ` daobang wang
2012-04-06 6:00 ` Jack Wang
2012-04-06 6:45 ` daobang wang
2012-04-06 6:49 ` daobang wang
2012-04-06 8:18 ` Stan Hoeppner
2012-04-06 8:45 ` daobang wang
2012-04-06 11:12 ` Stan Hoeppner
2012-04-18 2:23 ` daobang wang
2012-04-02 3:12 ` Stan Hoeppner
2012-04-01 10:33 ` David Brown
2012-04-01 12:28 ` John Robinson
2012-04-02 6:59 ` David Brown
[not found] ` <CA+res+QkLi7sxZrD-XOcbR47CeJ5gADf7P6pa1w1oMf8CKSB4g@mail.gmail.com>
2012-04-02 8:01 ` John Robinson
2012-04-02 10:01 ` Jack Wang
2012-04-02 10:28 ` John Robinson
2012-04-02 20:41 ` Stan Hoeppner [this message]
2012-04-02 5:43 ` Stan Hoeppner
2012-04-02 7:04 ` David Brown
2012-04-02 20:21 ` Stan Hoeppner
2012-04-01 4:52 ` Stan Hoeppner
2012-04-01 8:06 ` John Robinson
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