super slow back up over network, local all right 1

[rebelnorth]

I have several machines that are being backed up over an ethernet network through a autosensing 10/100 switch by arcserve 9.1 on a win 2000 machine. Recently, apparently with no change that I was informed of on the network, they suddenly started being backed up at between 6 and 8 MB per minute. I have no idea why. This is down from throughput in the 300+ range. Everything else seems to be running fine on the network with no slowdown. CA told me to reference document 18140 "Throughput issues with backups"

I did, and I checked to make sure the OS and Arcserve were patched up. They are. I have the latest drivers on the scsi and nic cards, the tape device has been cleaned, and to my knowledge is not attempting to do hardware comression. The CPU is not heavily used during backup. There is no hardrive space problem. Compatability between hardware devices should be fine since nothing changed physically, and all networked machines are affected. I should not need to switch from full duplex to half duplex since we are not using a hub, and the switch is autosensing. The switch shows no collision problems during a backup. I am using the client agent to do the backup, and I removed the client and reinstalled it, just to be sure, and did the same with the backup for open files. I had a virus client on a test machine that was not doing real time scanning. Even so I removed it entirely from the machine and still got the same speed. The Test machine has a 10/100 nic functioning at 100. All remote machines are affected thus. But there is no problem with excess packets over the network from or too the backup server.

I have seen the suggestions for modifying the tcp/ip settings in the registry suggested in earlier threads, but I am loathe to modify the registry when not more then a few days ago it worked fine with the registry set as it is now. Does anyone have an idea where I might have missed something?

Thanks in advance.
Ian

 

[TudorP]

Can you try to copy the same files you are backing up to your local machine? see what kind of throughput you get
Then try to do a local backup. see if you get the regular throughput of 300MB/min
cheers
TP

 

[rebelnorth]

Figured it out. I had to set all machines for half duplex even though I am using a switch, which makes sense now that I think about it.