Fustrating speed issue

[aurora]

Ok I have a very annoying speed issue that I have been trying to resolve for the past few days. Basically I am getting 1.86 mb/sec backup speeds, regardless of compression ratio. I have tested with 2:1 and 3:1 and the speed doesn't differ one tiny bit, it's still 1.86 mb/sec.

Before people say, I have read and followed all of the following document: http://seer.support.veritas.com/docs/231488.htm

I have ran HP diagnostic tools and can read from one hard drive (source) on average 9mb/sec and the other, 29mb/sec. Yet backing up to the tape is 1.86 mb/sec.

Note that the HP diagnostic software writes data into system memory and then backs this up to the tape, to elimate SCSI disk issues, and still... 1.86 mb/sec. The drive is a HP Ultrium drive that has a specification of 900mb/min, so this is far under achieveing in its current state.

CPU/Memory isn't even getting close to its limits, CPU was around 11% and memory had over 280mb free.

Controller is set to Wide Negotiation with auto detect speed. It's an Adaptec 29160LP Ultra 160 SCSI card that has no other devices other than the Ultrium drive on it. The cable is all of a few inches long and is of the 68pin variety. I have just tried updating the drivers for the Adaptec card but cannot reboot yet as it's a live/production server.

The thing that amazes me is the consistency of it, regardless of source. Something somewhere is definately throttling the bandwidth on the card/channel/tape drive to 1.86mb/sec...but what? and how can I find out? As stated, I have followed many documents to try and troubleshoot this.

This issue really is driving me mad, can somebody please give me a straw to grasp hold of? To be honest though, I'll be suprised if I get a reply as I've tried as good as everything documented on this site.

Thanks

[aurora]

More information that I had previously forgotten to include was the following:

Enable device for Backup Exec: Ticked
Pause device: Unticked
Enable compression: Ticked

Block size: 64k
Buffer size: 64k
Number of buffers: 10

Read/Write single block mode: Both unticked
Read/Write SCSI Pass-through mode: Both unticked

If I remember any more settings that you may possibly wish to know, I shall add another reply (as it doesn't let you edit your mesages).

Thanks

[Ken_Putnam]

Is the tape drive on it's own controller?

Are you current om firm,ware and drivers for the controller?

If you are using Veritas drivers, have you tried mfg drivers?

If you shut down all BackupExec services, does NTBackup get about the same throughput?

[Ken_Putnam]

Is the tape drive on it's own controller?

Are you current on firmware and drivers for the controller?

If you are using Veritas drivers, have you tried mfg drivers?

If you shut down all BackupExec services, does NTBackup get about the same throughput?

[Ken_Putnam]

Is the tape drive on it's own controller?

Are you current on firmware and drivers for the controller?

If you are using Veritas drivers, have you tried mfg drivers?

If you shut down all BackupExec services, does NTBackup get about the same throughput?

[aurora]

Thanks for the reply.

Is the tape drive on it's own controller? - YES

Are you current on firmware and drivers for the controller? - YES

If you are using Veritas drivers, have you tried mfg drivers? - YES

If you shut down all BackupExec services, does NTBackup get about the same throughput? - NOT TESTED

Although I cannot see the last one making much difference because I have tried backing up with other test programs and they still get the same speed as backup exec.

Thanks again for the reply, it's appreciated.

[shweta_rege]

Hello,


-- Kindly check the same backup with NT Backup and check the throughput..


NOTE : If we do not receive your reply within two business days, this post would be marked assumed answered
and would be moved to answered questions pool.

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[aurora]

Ok I will check in about 1 hour and post my results shortly after. Please do not assume answered because it really isn't, regardless of results, the backups need to operate properly within Backup Exec.

[aurora]

Speed was 1mb/sec :(

Where do I go from here? Any ideas?

Thanks

[aurora]

I think I've resolved this problem myself, or at least know what the problem is.

I have marked the question as answered and I shall open a new question if this is still an issue but I am confident I have found the solution.

[Ken_Putnam]

Just trying to determin whether the fault is in BackupExec or somewhere in the hardware

[Ken_Putnam]

What was the solution?


If you don't mind saying :)

[aurora]

Hi Ken,

I am going to try my resolution this evening hopefully, I shall let you know if I was correct. I am fairly confident I will be, but you never know ;)

I am thinking the problem is with ASYNC or AUTO being set as the maximum speed within the SCSI card. I am going to force 80mb/sec and hope for the best.

[Gauri_Ketkar]

Hi

Do update us on the resolution ...


Thank you
Gauri

[aurora]

I will, however it will not be until Monday morning when I return to work.

Please keep this thread open if you wish to know the outcome.

[Amruta_Bhide]

Hello,
We await your Response.

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Note : If we do not receive your reply within two business days, this post would be marked �assumed answered� and would be moved to �answered questions� pool.


Thanks.

[aurora]

I know, I am sorry.

I did not get change to reboot the live server on Friday evening, this will be done this evening and I shall post my results early tomorrow morning.

[Russ_Perry]

I'm betting the sync transfer setting on the SCSI card didn't make much difference...even at the lowest setting with wide negotiation off, 5 MB/S, throughput should be better than what you're getting. The only thing I have seen that will seem to govern the throughput to around 100 MB/M is the controller driver... Are you quite sure that you have the latest and greatest controller driver??

Russ

[aurora]

Hi Russ,

I have updated the controller driver to the latest but the changes to not take place until the reboot shortly... ;)

Results tomorrow morning when I arrive into work.

Thanks again

[aurora]

Backup now runs at 423-590mb/min, just as I thought. The limit now will be the speed it can read the disks as I tested this between 6-10mb/sec.