Re: Dell Perc 5/i Performance issues

On Sat, 19 Jun 2010, oizs wrote:

> Date: Sat, 19 Jun 2010 02:27:05 +0200
> From: oizs <oizs_at_freemail.hu>
> To: freebsd-current_at_freebsd.org
> Subject: Re: Dell Perc 5/i Performance issues
> 
> Im using the Samsung F3 disks, which can do 140MB/s sequentially. I have 
> tried different raids raid0 will do just as bad as raid5. I even tried one 
> disk which performed as expected 100MB/s+ reads and writes so I'm not sure 
> anymore what could be the problem. Maybe the controller hates samsung disks?
>

I have a 8-disk Samsung F1/F3 mixed setup under FreeBSD-current:
(fs)(root) mfiutil show drives
mfi0 Physical Drives:
(  932G) ONLINE <SAMSUNG HD103UJ 1118 serial=S13PJDWS500394> SATA slot 0
(  932G) ONLINE <SAMSUNG HD103UJ 1118 serial=S13PJDWS500033> SATA slot 1
(  932G) ONLINE <SAMSUNG HD103UJ 1113 serial=S13PJDWQC28106> SATA slot 2
(  932G) ONLINE <SAMSUNG HD103UJ 1113 serial=S13PJDWQC28108> SATA slot 3
(  932G) ONLINE <SAMSUNG HD103UJ 1104 serial=S13PJ1EPB00232> SATA slot 4
(  932G) ONLINE <ST31000340AS SD1A serial=9QJ18R8B> SATA slot 5
(  932G) ONLINE <SAMSUNG HD103UJ 1104 serial=S13PJ1EPB00066> SATA slot 6
(  932G) ONLINE <SAMSUNG HD103UJ 1104 serial=S13PJ1EPB00602> SATA slot 7

The disks are organized as JBOD disks.
Later on they form one ZFS pool:
config:

         NAME         STATE     READ WRITE CKSUM
         x            ONLINE       0     0     0
           mirror     ONLINE       0     0     0
             mfid0p4  ONLINE       0     0     0
             mfid1p4  ONLINE       0     0     0
           mirror     ONLINE       0     0     0
             mfid2p4  ONLINE       0     0     0
             mfid3p4  ONLINE       0     0     0
           mirror     ONLINE       0     0     0
             mfid4p4  ONLINE       0     0     0
             mfid5p4  ONLINE       0     0     0
           mirror     ONLINE       0     0     0
             mfid6p4  ONLINE       0     0     0
             mfid7p4  ONLINE       0     0     0
             ada0p3   ONLINE       0     0     0

 	(ada0 is there because mfid6 had some unreadable blocks lately)

I get ~370MiB/s writing performance using `iozone -s10g -r1m`.

While my samsung disks are problematic in the area of reliability
(I get occasional parity mismatches or read errors),
performance is good.

Have you enabled the disk caches as well?
Something like:
MegaCli -LdSetProp Cached -LALL -a0
MegaCli -LdSetProp NORA -LALL -a0
MegaCli -LdSetProp WB -LALL -a0
MegaCli -LdSetProp -EnDskCache -LALL -a0
(Only if having a USV of course)

Dunno if there is a mfiutil equivalent though.

Bye/2
---
Michael Reifenberger
Michael_at_Reifenberger.com
http://www.Reifenberger.com