ARCserve 2000 Version 7.0 - Decreased Throughput

[MikeRamalho]

Good Day Everyone,

Over the past couple of days, i've noticed that my backup jobs have increased in time.

Up until last Wednesday my backup up was taking about 10 hours to complete and had an AVG Throughput of 550mb/min

The past two backups i've run have taken 46 hours with an AVG throughput of 100mb/min.

Nothing has changed as i am still backing up the same job, the size of the job is relativly the same, about 230GB on a 320 tape.

Any ideas as to why the throughput would change so drastically?

Thank you

Mike

 

[davidmichel]

Check session by session to see if it is a specific session that is slow and this will help you to identify a problem with a specific target.

 

[MikeRamalho]

Hi DavidMichael,

I've checked the sessions and it's every session that is showing decreased throughput. Funny thing is that one day the backup runs at about 650mb/min while the next day it will run at 100mb/min. It is the whole job not just certain sessions.

Thanks

 

[davidmichel]

ok so it is a problem at the backup server.

If the backup of a volume on the backup server is just as slow as the backup of the target systems then it is not network related either.

Check for running applications at the time of the backup.

Performance Monitor is a good tool to use.

 

[MikeRamalho]

Thank you, i've updated drivers for the tape drive and will give it a go tonight and use performance montitor.

I'll let you know what happens tomorrow.

Cheers

 

[davidmichel]

ARCserve uses SCSI Pass Through instead of tape drive drivers so it is doubtful updating the tape drive drivers will help.

Also considering this just started happening a few days ago, it is more likely that software will not all of a sudden stop working well. More likely a change in the data, a new conflicting application, or hardware is the cause.

 

[MikeRamalho]

Thanks DavidMichael for the update, the throughput issues happen periodically.

I run two backups one overnight and one during the day. Somedays the night time one decreases in throughput and other days the day time one decreases. Its very random.

I also recieve the following error also usually once or twice a week:
E6300 Windows NT SCSI Port Error [ABSL:2050 CMD:ah Scsi Command entry]
E6300 WIndows NT SCSI Port Error [ABSL:2050 CMD:ah NT:79h 121]

I've updated SCSI drivers, reset cable and rebooted the server still no luck...

Any suggestions...

Thank you,

Michael

 

[davidmichel]

If it is always the same volume and multiple volumes are being backed up then look from some application running on that volume. Maybe a virus or spyware scan, or defrag.

Check the Event Viewer system log for an event from the controller at the time of the SCSI error.

Are there any other devices on the SCSI bus along with the tape drive?
What type of tape drive?
If the SCSI controller shares IRQ then move it to a different slot.