Will fiber link increase performance?

[momoko]

I have arcserve 2000 (sp4) attached to a win2k sp4 server (2.4 GHz). Backuping up locally I get 150 - 170MB per minute, backingup servers over my 100Mb Ethernet network I get 95 - 110MB per minute. (which means it takes about 17hours to backup 180GB of (compressed)data.

First are these speeds typical?

Second - will upgrading my link between the servers to a fibre link substantually increase performance?

Thanks

 

[ChaosCreator]

I use ASv9 and I get around 500-1000 MB/Min, but here's the difference - I'm using LTO drives and Gigabit Ethernet over copper. When determining/troubleshooting speed look at these areas:

1. Tape Technology - Drive throughput is a big factor.

2. Network Connectivity - Faster is usually better, but sometimes AS likes to work with Half-Duplex. Experiment. You mentioned Fiber - hey - it's definately an improvement, if the backplane of your switch will handle the throughput.

3. PCI I/O load - is your tape drive on the same SCSI card as your server's hard disk? Try splitting up the I/O to improve performance.

4. Server Horse Power - your 2.4Ghz sounds more then able to get 500-1000 MB/m throughputs.

5. The last thing to consider is file size. I've found that my big SQL jobs run fast, but my file servers run slower, and that's because there are more open / close requests involved in moving the data.

Hope this helps.

 

[momoko]

Just as follow-up I'm using LTO drives over 100MB ethernet all servers are running on the same planer card. It's using a 32bit PCI scsi card only connected to the 128T tape library.

I'll try coming in on the weekend and trying half duplex, but not so keen switching the servers permently to half duplex.

Thanks

Matt

 

[sobriant74]

I'm running AIT3 over 100MB, using a 64 bit PCI scsi card only running the tape drive. I get backup speeds closer to 180-220 MB per minute, but I think most of that is that the AIT3 drive is faster recording than LTO (it runs the tape over the head fewer times). I'm looking at switching all of my servers to 1000mb ethernet (3 of the six already are) and adding a gigabit switch in the server room, currently its a cisco catalyst 100mbps. I think that might get me even faster, but my point of this entry is that I think your bottleneck might really be your tape drive's record speed. I talked with a lot of vendors before going with AIT3 and I've been very happy with it.

 

[momoko]

the specs for the drive say 15/30MB per second...other issue is I'm using 32bit pci scsi adpater, but I think I should get 40MB throughput on that.

 

[momoko]

link to the drive info....if you are interested.

http://docs.us.dell.com/docs/stor-sys/128t/en/Drive_Manual/drimedia.htm

 

[Xen0n]

What kind of backup performance do you get for backing up your local hd? If that is poor also, switching to half duplex most likely won't help you. If you haven't already, you might want to try a newer scsi card driver.

Something else to check is whether or not your servers are set to Autodetect NIC speed and duplex settings. If you are, just lock them down to the duplex setting that you prefer (I'm assuming full duplex in this case) - on both the server and the switch. If that doesn't do the trick try leaving the backup server at full duplex and setting one of your file servers (preferably a non-production server of course) to half-duplex and see if that helps.

I almost forgot to mention that you may also want to check to see if you are using out of date nic drivers and verify if the firmware on your tape drives and library (if you are using one) are on CA's supported list.

One final thing to look into if nothing else resolves your problem is to use QCheck from NetIQ to test network throughput from your backup server to the backup clients. I was able to use this tool to identify that one of my servers had bad backup performance because of bad fiber (using gigabit over fiber)...

Good luck!

Michael