Arcserve 9 backup to disk is slow

[eedwards]

I am trying to backup ~150GB(95GB compressed) of data per night first to hard drive, then writing this to tape during the day. Need to keep this arrangement if possible. Server is Arcserve 9/Windows 2003, dual 3.2 processors, plenty of RAM writing to a raid 5 array of 10000rpm drives. The tape is an HP Ultrium 200/400. IE: nothing should slow this down.

I see significant increase from old system on most parts of backup. however, after limited testing, I am seeing the following:
A. Old system was ~20hrs writing to HD or Tape.
B. Writing directly to tape cut this in half; ~10 hrs.
C. Writing directly to disk, job takes ~16 hrs on new system.
D. Writing the data from the Drive on the server to tape, takes about an hour. (1 hour)

The slowdown appears to be on the server, but not the drives them selves. They serve the data to the tape very quickly, so there should be no issue with their speed. The only problem I see is that there is some problem with the way Arcserve writes the data to the Hard Drive versus the Tape Drive.

The Hard Drives are configured as File System Devices and the job is configured to use those as the target for the backup. Does anyone know of a problem with doing this or is there a better configuration of the base product? I cannot purchase any add-ons at this time, but I would not think that would be necessary. Thanks!

 

[davidmichel]

Is the backup source and the FSD target on the same controller?

Perhaps the slow down is at that level, and when going to tape it is going from one controller to another and so the bottleneck is avoided.

 

[eedwards]

I don't believe it is a controller issue because the server I have is dedicated to Backup duty only, so it pulls all data to be backed up from other servers. Whether writing to tape or to disk, the data is pushed in by the client agents via the network (10/100) and then Arcserve writes it to either the tape or the hard drive. I would think that the bottleneck would be the network connection, but that doesn't seem to be the case.

Thanks for your suggestion, though!

 

[davidmichel]

OK data source is the same - disk slow - tape fast

No reason to suspect the network, only place I can think of is the disk subsysem.

 

[eedwards]

Yes, data source is the same; writing to disk is slow, but I am not sure it is the disk subsystem to blame. The server is an HP DL380 with a raid 5 array of 4 x 148GB, 10000 rpm drives. No reason to believe it is slow, especially given that when I back up the 160+ GB data from the disk to the tape, it does this in 1 hour, and with speeds above 2GB/minute. The disk system is fast, but I can see where there could be a config issue with either the subsystem or the way Arcserve talks to it.

Thanks again for your help!

 

[SharedLibrary]

The Backup to disk should be about the same speed as a copy of files to that same disk, can you use that to get an idea of where the pefformance should be?

Try copying a set of folders from one of the remote machines to a folder on the target machine and based on the amoutn of data and the time it takes, you should be able to calculate the throughput... See if it is about the same as ARCserve, if so, then it's not an ARCserve problem if it is faster , then ARCserve might be the culprit.

 

[eedwards]

Sorry for my delayed response.

I tested and found that if I do a straight file copy, that it took 33 minutes to copy the files straight to the disk manually. It took Arcserve 1 hour, 15 minutes to do the same. To copy this same data to tape took 22 minutes. It appears to be Arcserve.

 

[data411]

Try NetVault, you can get a trial download at

http://www.bakbone.com/products/downloads.

It's easy to install and configure. I've had great experience with it.

 

[eedwards]

Well, I appreciate the suggestion, but I am kind of locked into Arcserve at the moment. I need to find a solution given the product I already own, rather than spending more money on something new. That includes any new Arcserve products. Shouldn't I expect that since I have the Arcserve server software backing up data on a server with a Client agent, that the speed of the backup should be faster than a manual copy operation?

 

[davidmichel]

Client Agent should be faster but not always,
test backups
set client agent priority to high
set client agent priority to low
bkup without client agent

oh, and ck for update to agent, either stand alone agent update or update included in latest SP.

 

[adobbie]

Hi eedwards, did you sort this in the end?

This is an old thread but I am experiencing similar performance issues with ARCServe r.11.1 - at the testing stage.

I get good performance until I try to run two (not tried any more than this yet) remote server backups concurrently. I get concurrent throughput of @ 650MB/min on each server over a dedicated GB backup LAN when writing to disk.

However, when one server finishes backup and starts verifying, its performance drops to about 6MB/min. I'm guessing this is because the verify process is reading from the array that the other server is writing to (the other server's performance remains reasonable). Once the first server's backup finishes verifying, the remaining server's backup completes with throughput around about 1.5GB/min.

The most obvious conclusion from this is to avoid running backups concurrently, but that was one of the principal benefits backup-to-disk was sold on - the idea being it would reduce my backup window by negating the need to buy multiple tape drives or have backup jobs queueing to use them.

Any suggestions on how I can improve performance while maintaining concurrent backup performance?

Cheers!