linux-kernel - Re: Slow Soft-RAID 5 performance

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.64.0707180626481.7659@p34.internal.lan>
Date:	Wed, 18 Jul 2007 06:28:46 -0400 (EDT)
From:	Justin Piszcz <jpiszcz@...idpixels.com>
To:	Rui Santos <rsantos@...popie.com>
cc:	Linux RAID <linux-raid@...r.kernel.org>,
	Linux Kernel <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...hat.com>, Neil Brown <neilb@...e.de>
Subject: Re: Slow Soft-RAID 5 performance



On Wed, 18 Jul 2007, Rui Santos wrote:

> Hi,
>
> I'm getting a strange slow performance behavior on a recently installed
> Server. Here are the details:
>
> Server: Asus AS-TS500-E4A
> Board: Asus DSBV-D (
> http://uk.asus.com/products.aspx?l1=9&l2=39&l3=299&l4=0&model=1210&modelmenu=2
> )
> Hard Drives: 3x Seagate ST3400620AS (
> http://www.seagate.com/ww/v/index.jsp?vgnextoid=8eff99f4fa74c010VgnVCM100000dd04090aRCRD&locale=en-US
> )
> I'm using the AHCI driver, although with ata_piix, the behavior is the
> same. Here's some info about the AHCI controler:
>

With three disks, if everything was perfect yeah 120MB/s writes.  When I 
had started out with 4 raptors I was getting 164MB/s read and write.  By 
default with no optimizations you will not get good speed.

With no optimizations with 10 raptors I get 180-200MB/s, with 
optimizations, 464MB/s write and 622MB/s read.

1. Use XFS if you wan't speed.
2. Use 128k, 256k or 1MiB chunk size.
3. Use 8192k, 16384k stripe_cache_size.
4. Use 65536 readahead size.

These are only some of the optimizations I use.

Justin.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/