From: Stan Hoeppner <stan@hardwarefreak.com>
To: daobang wang <wangdb1981@gmail.com>
Cc: "Mathias Burén" <mathias.buren@gmail.com>,
linux-raid <linux-raid@vger.kernel.org>
Subject: Re: RAID5 created by 8 disks works with xfs
Date: Sun, 01 Apr 2012 00:40:37 -0500 [thread overview]
Message-ID: <4F77EA55.6090004@hardwarefreak.com> (raw)
In-Reply-To: <CACwgYDMx6nQF-OwYj-BA+sZivUK=kmv2tPukgf5JGwA1vMTGrA@mail.gmail.com>
On 4/1/2012 12:12 AM, daobang wang wrote:
> Thank you very much!
> I got it, so we can remove the Volume Group and Logical Volume to save resource.
> And i will try RAID5 with 16 disks to write 96 total streams again.
Why do you keep insisting on RAID5?!?! It is not suitable for your
workload. It sucks Monday through Saturday and twice on Sunday for this
workload.
Test your 16 drive RAID5 array head to head with the linear array + XFS
architecture I gave you instructions to create, and report back your
results.
> I used the Linux kernel 2.6.26.4.
Which distro?
2.6.26 is *ancient* and has storage layer bugs. It does NOT have
delaylog, which was introduced in 2.6.35, and wasn't fully performant
until 2.6.38+.
You're building and testing a new platform with a terribly obsolete
distribution. You need a much newer kernel and distro. 3.0.x would be
best. Debian 6.0.4 with a backport 3.0.x kernel would be a good start.
> And we do not have BBWC
Then you must re-enable barriers or perennially suffer more filesystem
problems. I simply cannot emphasize enough how critical write barriers
are to filesystem consistency.
> The application has 16kb cache per stream, Is it possible to optimize
> it if we use 32kb or 64kb cache?
No. Read the app's documentation. This caching is to prevent dropped
frames in the recorded file. Increasing this value won't affect disk
performance.
--
Stan
next prev parent reply other threads:[~2012-04-01 5:40 UTC|newest]
Thread overview: 47+ 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 [this message]
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
2012-04-05 21:01 ` Stan Hoeppner
2012-04-06 0:25 ` daobang wang
2012-04-06 0:25 ` daobang wang
2012-04-06 2:33 ` daobang wang
2012-04-06 2:33 ` daobang wang
2012-04-06 6:00 ` Jack Wang
2012-04-06 6:00 ` Jack Wang
2012-04-06 6:45 ` daobang wang
2012-04-06 6:45 ` daobang wang
2012-04-06 6:49 ` daobang wang
2012-04-06 6:49 ` daobang wang
2012-04-06 8:18 ` Stan Hoeppner
2012-04-06 8:18 ` Stan Hoeppner
2012-04-06 8:45 ` daobang wang
2012-04-06 8:45 ` daobang wang
2012-04-06 11:12 ` Stan Hoeppner
2012-04-06 11:12 ` Stan Hoeppner
2012-04-18 2:23 ` daobang wang
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
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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