Poor Duplicate Job Speeds

[beyset06]

Our current backup strategy is to backup to disk and then have a duplicate job that writes the job to tape. The current throughput going to tape on the duplicate job is on average 1000MB/Min. We are backing up to a TS3500 tape library with an LTO4 tape drive connected to our backup server via fiber channel. I have tried several different configurations with the disk subsystem where we are backing up to thinking that it was the problem. If I run backup of just the BKF files on the disk I can achieve around 6000MB/min. I realize that running that job is complete different from a duplicate job but it at least it shows that I can get higher rates then what I am getting. I opened a ticket with Symantec and spoke with a tech support rep who told me that I should be expecting rates of 1000MB/min on duplicate jobs, and there is nothing else I can do. I have installed diskeeper on our backup server to keep fragmentation down but I haven't seen any improvements with the speed. Any help would be appreciated as we will be looking into using other backup software soon.

 

[teiva-boy]

 So doing a backup of the BKF, your throughput is 6000MB/min?  And doing a duplicate of the D2D backup is only 1000MB/min?  

It's hard to read when you dont use paragraphs...

I'd call back into support, and ask for a duty manager to escalate your case.  Perhaps the tier of support you were on was umm "not up to snuff," when it comes to knowledge.

[Ckidd_Ben]

I am also having a very similiar problem.

My duplicate backup starts out at 5000MB/min and progressivly slows down to a painful 300MB/min.  My CPU usage also progressivly builds from 50% to 100%.

In my case, the initial backup is done to a 4TB Raid5 array.  The duplicate is done from the 4TB array to a single 1TB removable eSATA hard drive.

I've tested the 1TB removable dive and it has a minimum 50MB/sec write rate.  That traslates to 3000MB/min.  It also takes an extremely painfull 30 hours to perform the duplicate job.  The backup file is just about 400GB.  If I manually drag and drop the file from the 4TB to the 1TB, it takes 3.5hours.  Or about 1900MB/min.  Still not stellar but WAY more than 300MB/min.

These questions are all over the forums but never seems to get answered.

This is on Windows 2000 Server SP4 using BackupExec12.5.  The 4TB array is on an 3ware/AMCC 9650SE RAID controller x8 PCIe.  The 1TB external drive is on a Silicon Image 3132 x4 PCIe controller.  The server has dual 3.2GHz Zeon Processors with 4GB of ram.

Thanks,
              Ben

[CraigV]

If the library is connected via FC, does that mean you have a SAN in place? THe ideal world would see you running that initial backup to a SAN-presented disk, and from there duplicating to tape. You'd have to have SAN SSO in place to take full advantage of your SAN's speed.
The slow down could be that the tape drive is not receiving data as quickly as it should, and it's there not spooling as fast as it might.
See what happens if you increase the size of your buffer on your tape drive.

[DominikG]

As far as I know, this is a known issue.
This issue got improved with every release since now, but does not get near the performance of the real backup job.
It has been way worse than now in former releases.


If you get any new information on this, let me (and all others) know.
I had a customer support call a time ago, and the only feedback I could get after talking to support, product management, and so on was, what I wrote above...

[Ckidd_Ben]

I should also mention that BESR 8.5 also has the same problem.  Transfers progressively slow to a crawl as file size increases.

Offsite copy took 16 hours to copy primary 390GB recovery point but only 6 minutes to copy two incremental points totaling 36GB.

390GB @ 400MB/min
36GB @ 6000MB/min

This is really aggravating.  I came in this morning to a server at 100% load for a simple file copy operation.  Offsite copy is a great idea but I'm going back to my old robocopy scripts until this bug is fixed.

[RHSFC]

 I am having to same problem. ...or maybe a bit worse. My duplicate backup jobs run at a maximum speed of 250 or 300MB/min. They also sometime go down to 80Mb/min and i am in a state of panic since i can't finish all my backups in 24hrs. I am backing up about 750GB of data daily and i am using the same scenario as beyset06 has with a difference in the backup library which is a DELL PowerVault 132T.

Any recomendations will be greatly appreciated.