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philcouto

3 Posts

59840

April 26th, 2007 21:00

Poweredge 860 Raid 1 (Mirroring)

Has anyone had problems in the past with the Dell Poweredge 860 RAC Server and configuring RAID-1? When configuring the system for RAID-1, it performs extremely slow. I have previously configured the same system to use RAID-0 and it did perform extremely fast, the way it should. i have a SAS controller with two SATA drives. Any ideas? 

philcouto

3 Posts

May 3rd, 2007 19:00

Actually, I was able to fix this problem. Update your SAS 5 firmware. Updating the firmware apparently fixed the issue.

mike_tcis

15 Posts

May 3rd, 2007 19:00

We are having the exact same problem.  PE860, SAS 5i/R controller, 2 x 500GB Maxtor MaxLine Pro drives, latest system, RAID BIOS, and latest drivers, Win2003 SP2 + all patches as of 05/03/07.

philcouto

3 Posts

May 3rd, 2007 20:00

There's also a windows Q-logic driver update. Have you tried that?

mike_tcis

15 Posts

May 3rd, 2007 20:00

Unfortunately I'm already running the latest firmware, v 00.10.49.00.06.12.02.00.  Creating/writing files is still extremely slow.
 
 

dmose

12 Posts

June 12th, 2007 04:00

Experiencing the same issue on a PE860
 
2xST3160812AS 160GB firmware:  3.ADJ
Perc 5/iR (SAS1068) firmware: 00.10.49.00.06.12.02.00 Driver: 1.24.04.00
Windows Server 2003 DataCenter x64 RC2
 
All latest updates.
 
The issue is Write-Caching is set to Write-Through by default and for protection because these adapters do not have onboard battery.  Also they do not have onboard cache which typically high-end controllers do so I'm guessing the driver developers set this to write-through but left us no way to turn it to write-back.
 
You can safely use write-back if your system is on UPS - powerfailure you set a graceful shutdown or just ride out the surge and you won't lose any data - a good compromise over RAID 0 risk (ie disk failure is more catasrophic then rebooting your server and having your users wait a few minutes)
 
I have a dell rep looking into the issue hopefully he finds a way to enable this setting.
 
UNIX team has successfully enabled write-through and experienced much faster writes:
 
 
 

dimitri wrote:

> Thanks for the info Scott,

>

> Just out of curiosity: are you assuming there is an app to control

> this setting in windows or have you actually heard of one? The reason

> I ask is because DELL has their Open Management suite which *usually*

> lets you change raid settings on their PERC series controllers however

> for this particular one (5/ir) you can't change any settings.

Dell has told me that their OpenManage suite will control this. I haven't seen it in myself, but I hope to soon. The SAS-5 performance issues are well known to them, so if you contact them they should know how to answer your questions.

>

> So that brings me to my other thought - why would they leave this

> configuration out? Because the unit doesn't have battery backup

> capability or because they were too lazy to code it into their application?

The MPT-SAS controller has no cache on it. What is at issue is the SATA write cache. Enabling the write cache on any kind of drive is dangerous, whether it's SCSI, SATA, or SAS, so it's _always_ turned off by default. Unfortunately, the lack of NCQ (tagged queueing support) for SATA makes the performance penalty very high and thus much more visible than SAS/SCSI.

>

> Anyhow, thanks for the information

>

> Btw, did users experience normal or increased write i/o on freeBSD

> with these settings enabled?

I added a feature to FreeBSD 6 and 7 last week that enables the SATA write cache on all drives directly connected to an MPT-SAS controller.

If you want to try this out, you'll need to update your kernel sources and add the following line to /boot/loader.conf:

hw.mpt.enable_sata_wc=1

Most people are reporting a significant increase in write performance.
 
 

dmose

12 Posts

June 13th, 2007 03:00

Altravia

2 Posts

November 14th, 2007 15:00

Hi
I have the same problem
I boght 4 different 860, I upgrade all driver,  install all OS (Ubuntu, Suse, Debhian etc.) in any case the memory are full whitout operation
 
If you do the "top" command to prompt you can see your memory, is full whitout operation.
 
You can solve the problem only if you remove the ride controller.
 
My company call for many time DELL to not sell more 860 whit SAS/SATA controller and SATA disk but the CEO receive only new contract for new server.
 
I hope in future the DELL company not sell this configuration, Whe have more than 15 Dell server (the old 850 are perfect) and only whit this configuration whe cant resolve the problem and DELL not work to solve the problem.
 
Maybe whit SAS disk  the server work well but DELL, My company ask if this is the right way and ask to buy the SAS disk if DELL confirm the problem and.....nothing happend.
 
In any case you can remove the ride controller and the server are incredible fast and working well, you can use a software ride. :-(
 
 
Have nice time
 

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