IDE-RAID Drive Performance

IDE-RAID Drive Performance

[Nicklas Bondesson]

Hi!

I think i'm getting really bad values from my disks. It's two Western
Digital WD800JB-00DUA3 (Special Edition 8 MB cache) disks connected to a
Promise TX2000 (PDC20271) card (RAID1 using ataraid under Linux 2.4.23).

The disks are setup with hdparm at boot time:

/sbin/hdparm -X69 -d1 -u1 -m16 -c3 /dev/hda 
/sbin/hdparm -X69 -d1 -u1 -m16 -c3 /dev/hdc

When running hdparm -tT I get the following:

/dev/hda:
 Timing buffer-cache reads:   128 MB in  1.13 seconds =113.27 MB/sec
 Timing buffered disk reads:  64 MB in  2.46 seconds = 26.02 MB/sec

/dev/hdc:
 Timing buffer-cache reads:   128 MB in  1.13 seconds =113.27 MB/sec
 Timing buffered disk reads:  64 MB in  2.47 seconds = 25.91 MB/sec

Are these normal values? I don't think so. Please advise.

/Nicke

Re: IDE-RAID Drive Performance

[Nuno Alexandre]

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On Tue, 30 Dec 2003 11:44:01 +0100 
Mr(s): Nicklas Bondesson wrote:

> Hi!
> 
> I think i'm getting really bad values from my disks. It's two Western
> Digital WD800JB-00DUA3 (Special Edition 8 MB cache) disks connected to a
> Promise TX2000 (PDC20271) card (RAID1 using ataraid under Linux 2.4.23).
> 
> The disks are setup with hdparm at boot time:
> 
> /sbin/hdparm -X69 -d1 -u1 -m16 -c3 /dev/hda 
> /sbin/hdparm -X69 -d1 -u1 -m16 -c3 /dev/hdc
> 
> When running hdparm -tT I get the following:
> 
> /dev/hda:
>  Timing buffer-cache reads:   128 MB in  1.13 seconds =113.27 MB/sec
>  Timing buffered disk reads:  64 MB in  2.46 seconds = 26.02 MB/sec
> 
> /dev/hdc:
>  Timing buffer-cache reads:   128 MB in  1.13 seconds =113.27 MB/sec
>  Timing buffered disk reads:  64 MB in  2.47 seconds = 25.91 MB/sec
> 
> Are these normal values? I don't think so. Please advise.
> 
> /Nicke

Hi.
This is what i get with a Maxtor 6Y120L0 (2MB cache):

/dev/hda:
 Timing buffer-cache reads:   1320 MB in  2.00 seconds = 659.44 MB/sec
 Timing buffered disk reads:  140 MB in  3.02 seconds =  46.40 MB/sec

Using:
-d1 -u1 -m16 -c3 -W1 -A1 -k1 -X70 -a 8192

I'm not using raid, its a single disk connected to IDE1 on the motherboard.

Maybe you can try those parameters and see if it helps :)
-- 
Best regards - Nuno Alexandre - na@imaginere.dk
Gpg: EA74637D - http://imaginere.dk - iM:ikaro@jabber.org

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Re: IDE-RAID Drive Performance

[Bob]

Nuno Alexandre wrote:

>On Tue, 30 Dec 2003 11:44:01 +0100 
>Mr(s): Nicklas Bondesson wrote:
>
>  
>
>>Hi!
>>
>>I think i'm getting really bad values from my disks. It's two Western
>>Digital WD800JB-00DUA3 (Special Edition 8 MB cache) disks connected to a
>>Promise TX2000 (PDC20271) card (RAID1 using ataraid under Linux 2.4.23).
>>
>>The disks are setup with hdparm at boot time:
>>
>>/sbin/hdparm -X69 -d1 -u1 -m16 -c3 /dev/hda 
>>/sbin/hdparm -X69 -d1 -u1 -m16 -c3 /dev/hdc
>>
>>When running hdparm -tT I get the following:
>>
>>/dev/hda:
>> Timing buffer-cache reads:   128 MB in  1.13 seconds =113.27 MB/sec
>> Timing buffered disk reads:  64 MB in  2.46 seconds = 26.02 MB/sec
>>
>>/dev/hdc:
>> Timing buffer-cache reads:   128 MB in  1.13 seconds =113.27 MB/sec
>> Timing buffered disk reads:  64 MB in  2.47 seconds = 25.91 MB/sec
>>
>>Are these normal values? I don't think so. Please advise.
>>
>>/Nicke
>>    
>>
>
>Hi.
>This is what i get with a Maxtor 6Y120L0 (2MB cache):
>
>/dev/hda:
> Timing buffer-cache reads:   1320 MB in  2.00 seconds = 659.44 MB/sec
> Timing buffered disk reads:  140 MB in  3.02 seconds =  46.40 MB/sec
>
>Using:
>-d1 -u1 -m16 -c3 -W1 -A1 -k1 -X70 -a 8192
>
>I'm not using raid, its a single disk connected to IDE1 on the motherboard.
>
>Maybe you can try those parameters and see if it helps :)
>  
>
I have two promise cards and four Maxtor
DiamondMax Plus9 60G with 8MB cache each
hdparm -d1 -u1 -m16 -c1 -W1 -A1 -k1 -X70 -a 8192

and my raid0 is software, linux, not the promise chip's raid

on each drive I see 900 MB/s 47.2 MB/s
and on /dev/md/2 /tmp with four drives
four partitions I see 900 MB/s 94 MB/s

that's with 64k raid chunk, reiser 4096b blocks

Linux says 2048k raid chunk would minimize
seek time for better real world performance. It
doesn't work better with hdparm -tT but that's not
realworld. My version of reiserfs doesn't allow
changing the block size.

-Bob D

Re: IDE-RAID Drive Performance

[Andre Tomt]

On Tue, 2003-12-30 at 12:21, Nuno Alexandre wrote:
> /dev/hda:
>  Timing buffer-cache reads:   1320 MB in  2.00 seconds = 659.44 MB/sec
>  Timing buffered disk reads:  140 MB in  3.02 seconds =  46.40 MB/sec
> 
> Using:
> -d1 -u1 -m16 -c3 -W1 -A1 -k1 -X70 -a 8192

Wow, slow down for a minute. Most IDE chipset drivers does a excellent
job at autotuning the max *safe settings* for your drive/chipset
combination. Mucking around with hdparm parameters blindfolded will only
cause you grief in form of data loss and system instability sooner than
later.

Usually when one gets into performance problems with IDE in Linux, the
chipset specific driver is not enabled, making the system fallback to
the generic driver - OR the drive and controller combination is
considered unsafe with faster settings.

Without any user intervention at all, my Seagate 7200 120G's does 55MB/s
in the infamious hdparm test, on a VIA KT266 based board, both in
2.6.1-rc1 and 2.4.23.

RE: IDE-RAID Drive Performance

[Nicklas Bondesson]

I don't know if you have read my latest post regarding this. anyway here it
is :)

It was the PCI latency value that was wrong. It was set to 0 in the BIOS so
I have changed it now to 64. I now get the following figures! :) BTW I'm
running two Western Digital WD800JB-00DUA3 (Special Edition 8 MB cache)
disks connected to a Promise TX2000 (PDC20271) card (RAID1 using ataraid
(pdcraid) drivers).

hdparm:

/dev/hda:
 Timing buffer-cache reads:   128 MB in  1.12 seconds =114.29 MB/sec
 Timing buffered disk reads:  64 MB in  1.53 seconds = 41.83 MB/sec

bonnie:

Version 1.02b       ------Sequential Output------ --Sequential Input-
--Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block--
--Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec
%CP
gollum         800M  4681  98 37827  76 17590  30  4888  95 39400  26 310.4
3
                    ------Sequential Create------ --------Random
Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read---
-Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec
%CP
                 16   310  99 +++++ +++ 21319 100   329  99 +++++ +++  1766
96
gollum,800M,4681,98,37827,76,17590,30,4888,95,39400,26,310.4,3,16,310,99,+++
++,+++,21319,100,329,99,+++++,+++,1766,96 

Thanks for the help!

/Nicke 

-----Original Message-----
From: Andre Tomt [mailto:lkml@tomt.net] 
Sent: den 3 januari 2004 15:00
To: Nuno Alexandre
Cc: linux-kernel@vger.kernel.org; Nicklas Bondesson
Subject: Re: IDE-RAID Drive Performance

On Tue, 2003-12-30 at 12:21, Nuno Alexandre wrote:
> /dev/hda:
>  Timing buffer-cache reads:   1320 MB in  2.00 seconds = 659.44 MB/sec
>  Timing buffered disk reads:  140 MB in  3.02 seconds =  46.40 MB/sec
> 
> Using:
> -d1 -u1 -m16 -c3 -W1 -A1 -k1 -X70 -a 8192

Wow, slow down for a minute. Most IDE chipset drivers does a excellent job
at autotuning the max *safe settings* for your drive/chipset combination.
Mucking around with hdparm parameters blindfolded will only cause you grief
in form of data loss and system instability sooner than later.

Usually when one gets into performance problems with IDE in Linux, the
chipset specific driver is not enabled, making the system fallback to the
generic driver - OR the drive and controller combination is considered
unsafe with faster settings.

Without any user intervention at all, my Seagate 7200 120G's does 55MB/s in
the infamious hdparm test, on a VIA KT266 based board, both in
2.6.1-rc1 and 2.4.23.