| Author |
Topic |
|
izaltsman
A custom title
1139 Posts |
 Posted - 2004-12-01 : 16:55:00
|
| Hi all!I've got a question for anyone, who has their SQL boxes connected to a SAN... I've got a server with a QLogic's QL2300 HBA, which is experiencing a problem, described in this KB article: http://support.microsoft.com/default.aspx?scid=kb;en-us;329075 A fix, suggested in the article, is to lower the value of the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\<your HBA driver here>\Parameters\Device\NumberOfRequestsI am trying to figure out what number to set this key value to (I need the value to be low enough to fix the errors I am currently seeing, yet high enough to not result in a major performance decrease). Currently the NumberOfRequests on my server is set at 150 (I believe that's the default). Could you let me know what number you are setting yours to?Thanks in advance!!! |
|
|
derrickleggett
Pointy Haired Yak DBA
4184 Posts |
Posted - 2004-12-01 : 17:22:25
|
| Are you using dynamic disks?MeanOldDBAderrickleggett@hotmail.comWhen life gives you a lemon, fire the DBA. |
 |
|
|
izaltsman
A custom title
1139 Posts |
Posted - 2004-12-01 : 17:29:22
|
| Yep, using dynamic disk. |
|
|
|
MichaelP
Jedi Yak
2489 Posts |
Posted - 2004-12-01 : 18:07:57
|
| Are you using MS Clustering?I'll have to look at my setting on my Qlogic HBA's. Give me a few.Michael<Yoda>Use the Search page you must. Find the answer you will.</Yoda> |
|
|
|
izaltsman
A custom title
1139 Posts |
Posted - 2004-12-01 : 18:25:20
|
| No, no clustering. |
|
|
|
MichaelP
Jedi Yak
2489 Posts |
Posted - 2004-12-01 : 18:50:20
|
| Doh, I'm running Emulux!Michael<Yoda>Use the Search page you must. Find the answer you will.</Yoda> |
|
|
|
derrickleggett
Pointy Haired Yak DBA
4184 Posts |
Posted - 2004-12-01 : 21:12:52
|
| I didn't change any settings for the QLogic HBA cards. I have the 2300 series also. I've got both the single and double HBA's. We're not using dynamic disks though. Why did you choose to go that route? Are you on 2000 or 2003? What kind of a SAN is it?MeanOldDBAderrickleggett@hotmail.comWhen life gives you a lemon, fire the DBA. |
|
|
|
izaltsman
A custom title
1139 Posts |
Posted - 2004-12-02 : 09:22:46
|
| I am on Windows 2000.I use dynamic disks for two reasons:a) I can expand them on the fly. b) According to some of the benchmarks I've seen, dynamic disks perform slightly better than basic ones (personally, I haven't noticed any difference though). My SAN is a XIOTech Magnitude 3d. |
|
|
|
MichaelP
Jedi Yak
2489 Posts |
Posted - 2004-12-02 : 15:31:51
|
| Well, for future reference, here's this.Dynamic Disks + MS Clustering == BAD!!Maybe dynamic disks are part of the problem here as well? I think I'd probably give MS a call on this one, or your SAN support folks.Michael<Yoda>Use the Search page you must. Find the answer you will.</Yoda> |
|
|
|
derrickleggett
Pointy Haired Yak DBA
4184 Posts |
Posted - 2004-12-04 : 21:56:20
|
| I wouldn't use dynamic disks with a SAN unless I had Windows 2003 if I were you. Is this an EMC by any chance?MeanOldDBAderrickleggett@hotmail.comWhen life gives you a lemon, fire the DBA. |
|
|
|
izaltsman
A custom title
1139 Posts |
Posted - 2004-12-06 : 17:31:17
|
| I lowered the registry key value to 128 on friday... So far the problem hasn't reappeared, and performance hasn't dropped. Derrick, Michael, thanks for bringing up the dynamic disks issues, I'll do some testing to see if I want to revert back to basic disks. PSThe manufacturer of this SAN is a company, called Xiotech. |
|
|
|
ruan4u
Posting Yak Master
132 Posts |
Posted - 2004-12-07 : 09:09:40
|
| My network guys have moved everything inot SAN. What should be done,or things one should know when the SAN is going to have SQL server and live data? |
|
|
|
MichaelP
Jedi Yak
2489 Posts |
|
|
ruan4u
Posting Yak Master
132 Posts |
Posted - 2004-12-07 : 13:43:48
|
| thanks michael.apart from query execution plan,is there anyother thing that i need to check for database performance? |
|
|
|
|
HBA-related registry settings