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Slow file access - please assist :(

Slow file access - please assist :(

I am having a heck of a time here with a Proliant ML370 G3 and file access on a ~320gb partition of the SmartArray 532 card.

It seems that small files take a long time to read / write to the drive. A folder of 30 files for a combined size of 1/2bm (half a meg) take upwards of 2 minutes to copy to a different location on the same drive. Where as 2 files combined for 50mb will take less than 30 seconds to copy to the same drive.

The OS is 2003 server standard, single proc 3.0 xeon, 2 gb of ram, boot.ini has /3GB parameter (added after these problems, no help)

The 532 smart array is firmware 2.56, cache enabled, 100% Read, 0% Write (just left as default) 6 72gb drives make up one large drive and the Windows OS is split into 3 logical drives of 4gb/20gb/315gb. The 315 partition is the data partition where these files are being copied around to/from (in this case, E: drive)

Allocation unts are 4096 btes for that partition. Chkdsk reports 0 bad sectors but claims 'Chkdsk discovered free space marked as allocated in the master file table (MFT) bitmap' I'll have to run a chkdsk /f /r this weekend when the server isn't being utilized.

This is a production box upgraded from NT 4.0 PDC to a 2003 Server (in place upgrade). The data was restored from tape to the new server via Veritas backup exec 9.0

Any suggestions *greatly* appreciated.
11 REPLIES

Re: Slow file access - please assist :(

Quick update:

I tried creating a folder on the D: drive (20 gb partition) and file copy access is *fast*, E: still chokes.

I've excluded all antivirus scanning of E: and still no dice.
Martin Balaj
Frequent Advisor

Re: Slow file access - please assist :(

Try bigger alloc. units ,like 16kb .
Prashant (I am Back)
Honored Contributor

Re: Slow file access - please assist :(

Hi,

Please run the attached utility and check the performance for same.

REgards,
Prashant S.
Nothing is impossible
SAKET_5
Honored Contributor

Re: Slow file access - please assist :(

Hi Martin,

A couple of points:
1. You do not mention any fragmentation analysis on E:\. Do you use Windows built-in defragmenter or any other software? Could you perform a fragmentation analysis and post the results.
2. Could you also confirm through the fragmentation analysis result about MFT fragmentation. Did you reserve MFT Zone space (by specifying a vaule to the "MFTZoneReservation" value in the Windows registry) when you were first setting up your registry?
3. What is your average file size, frag analysis would indicate that too?
4.How much free space have you got on your disk volume?
5. From HP web site, download PAT (performance assessment utility) and run disk volume performance test or you could use something like Nbench (searh on google, you will hit it in less than a sec), post some results too. These tools are aimed at pinpointing errors or to show comparative results between various volumes.
6.Have you enabled disk caching from Device Manager on Windows, if you have not try enabling them, see what difference it makes, I would hope that it will make a noticeable difference,

Anyway, enough thoughts for now, please post your results.

More than willing to help and don't forget to assign points:)

Regards,

Re: Slow file access - please assist :(

First off, thank you (and the previous poster for the tool) for taking the time to respond.

A couple of points:
1. You do not mention any fragmentation analysis on E:\. Do you use Windows built-in defragmenter or any other software? Could you perform a fragmentation analysis and post the results.


I just use 2003 Server's Chkdsk, I had a bunch of messed up security ids on a lot of files that were fixed last week with a run of it, though I didn't use the /R option of chkdsk.

It seems this week, however, there are more problems with the drive as Chkdsk failed to proceed to stage 3 (see attachment).

Last week it ran through the entire process but prior to it, I took a log as well and here were the results.
---clip from stage 3---
Replacing invalid security id with default security id for file 1199770.
Replacing invalid security id with default security id for file 1199772.
100 percent completed.
Security descriptor verification completed.
CHKDSK discovered free space marked as allocated in the volume bitmap.
Windows found problems with the file system.
Run CHKDSK with the /F (fix) option to correct these.

331043422 KB total disk space.
75801756 KB in 1146897 files.
241548 KB in 52799 indexes.
0 KB in bad sectors.
1277618 KB in use by the system.
65536 KB occupied by the log file.
253722500 KB available on disk.

4096 bytes in each allocation unit.
82760855 total allocation units on disk.
63430625 allocation units available on disk.
-----

2. Could you also confirm through the fragmentation analysis result about MFT fragmentation. Did you reserve MFT Zone space (by specifying a vaule to the "MFTZoneReservation" value in the Windows registry) when you were first setting up your registry?

Chdsk reports MFT error and I *did not* set aside MFT zone space (this is something I've never even heard of before)

3. What is your average file size, frag analysis would indicate that too?

See 1

4.How much free space have you got on your disk volume?

260gb free space

5. From HP web site, download PAT (performance assessment utility) and run disk volume performance test or you could use something like Nbench (searh on google, you will hit it in less than a sec), post some results too. These tools are aimed at pinpointing errors or to show comparative results between various volumes.

Will check into that file and get back.

6.Have you enabled disk caching from Device Manager on Windows, if you have not try enabling them, see what difference it makes, I would hope that it will make a noticeable difference,

I tried enabling write caching from device manager but it wouldn't save it, the box kept coming unchecked when I went back into it. Perhaps there is a setting on the card that over-rides this?

This is our first server in a long time and definitely a lot of changes on the OS since NT 4.0 so I'm green in a few areas now. I appreciate the assistance.

Anyway, enough thoughts for now, please post your results.

More than willing to help and don't forget to assign points:)

Done :)

Re: Slow file access - please assist :(

Quick update agian:

I just tried to run the PAT on drive e: but even doing the 'estimate run' (first radial box) it got to step 4 of 5 and pretty much hung (not responding) within minutes I had a few users calling saying they could do nothing on that server so I was forced to end task and things are ok again (relatively speaking).

Tuesday night off hours I'll run the chkdsk /f /r on the drive and then PAT on the drive again.

Re: Slow file access - please assist :(

Whoops, I had my head up my ass in the last message. I didn't include the fragmentation report, but rather chkdsk.

Please find attached Defrag report (2003 server)

Re: Slow file access - please assist :(

PAT estimate run returned 2.73MB/min transfer rate. Ugh...

Re: Slow file access - please assist :(

Doh, I wish there was an edit button:

Result of Estimation Test for drive E:
Estimate Time: 277min, 57sec (45334.4MB)
Transfer Rate: 2.72mb/Sec

(2.72 a second, no a min)

Duane Putnam
Occasional Visitor

Re: Slow file access - please assist :(

Martin,

Did you ever manage to get this resolved? If so, how? TIA

Re: Slow file access - please assist :(

I did get it resolved in fact. Sorry for not posting it here when I found the solution. I was simply so elated that I went out on a large bender that weekend and my short term memory was destroyed.

The problem was with the OS itself in fact, though it may have been due to the in-place upgrade. I'm not 100% certain to this day of the cause, I have a few other 2003 machines that never exhibited this problem.

To fix it I had to change a registry key from the default value of '2' to '1' and it fixed it. Now this key defaults to 2 and to change it you actually have to add it and then change the value to a 1 (reboot required)

http://support.microsoft.com/?id=328890

highlights here:

Subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\
Entry: TcpAckFrequency
Value Type: REG_DWORD, number
Valid Range: 0-255
Default: 2
Description: Specifies the number of ACKs that will be outstanding before the delayed ACK timer is ignored. Microsoft does not recommend changing the default value without careful study of the environment. For more information, visit the following
----

Another article here mentions that changing this key may not actually do anything unless you first apply a hot fix:

Changing the TcpAckFrequency Value to 1 Does Not Have Any Effect
http://support.microsoft.com/?id=815230
----

Thankfully in our case we didn't have to apply any fixes first. We just added the key, changed the value to a 1 and low and behold the server started to function like a 10k server should :)

As a side note, we've had no negative fallout from changing the value from a 2 to 1 and it's been running great now for the last month or so.

Regards,

Martin