Macs freeze the server

[MTM]

As of late we have been experiencing intermittent freezing of Retrospect Server during backups. Here’s out configuration:

 

 

 

PC Server (Pentium III 500 MHz) running NT4 Server SP6 w/ 512 MB RAM, 2 SCSI hard drives, one Seagate DAT DDS 4mm SCSI tape drive. Incremental backups are scheduled for Mon-Thurs nights and Friday is a recycle.

 

 

 

Backup clients: There are 15 PCs all running WinNT 4 Workstation SP5. There are 7 Macs - G3s and G4s - all running OS 9.1

 

 

 

We have been using Retrospect Server (5.6.127) since Feb of this year with no problems whatsoever. But within the past month or so Retrospect will freeze while copying files from one of the Macs. This requires that the sever be restarted and the backup rerun – a real pain. During the rerunning of the backup no problems are encountered – except this last week. We thought initially that Retrospect was stumbling on a specific file, but then the freeze started to happen during the copying of files from two other Macs.

 

 

 

We have run all the Windows diagnostics and have monitored the network traffic logs for possible data losses but all is normal and since the backups are run during the night this is the only network activity.

 

 

 

The only solution I can come up with at the moment is to reinstall Retrospect on the server and on the Macs that have been involved.

 

 

 

Anyone experienced this behavior? Any easier fix suggestions would be appreciated.

 

 

 

Thanks,

 

 

 

M

 

 

[AmyJ]

Unfortunatley, there is no easy answer. From your post, I see that it worked fine for months, then it locked up backing up a particular computer, and now it is locking up backing up more then one computer.

 

 

 

There are 4 general variables involved (each of which have their own set of variables that you can troubleshoot).

 

 

 

1. Backup Server

 

2. Clients

 

3. Backup Device

 

4. Network

 

 

 

Any one of these could be the culprit - and the first step is to isolate where the problem is coming from.

 

 

 

Does the freeze always happen only on selected clients? If so, what hardware variables do these clients have in comon? Same router? Same hub?

 

 

 

If the problem begins occuring on any client, you could have a problem with the network, the backup computer or the backup device.

 

 

 

There are many possibilities - I would search the Knowledgebasecolor=blue> for concise troubleshooting on networking, computers and backup devices. You'll find things like trying a crossover cable between a troublesome client and the server, checking network drivers on the server, try different tapes, clean the heads on the tape drive, try a different backup computer as a test. Until the problem can be isolated further, it is really difficult to suggest thorough troubleshooting. Many times, these issues are device related rather then client related.

 

 

 

SCSI Troubleshooting:

 

http://www.dantz.com/index.php3?SCREEN=kbase&ACTION=KBASE&id=26499

 

 

 

 

[MTM]

I am fairly savvy with this little NT 4 mixed network that was installed 18 months ago in a new building. All computers are connected via Cat5 through a 10/100BaseT Nortel Bay Systems Managed Switch and one 3Com hub. Before coming on this forum to seek assistance I stepped through the same variables that you listed and have been attempting to isolate the source of the problem, but so far nothing.

 

 

 

To answer your questions:

 

 

 

1. Retrospect has hung on 4 different Macs (total of 11 hangs in a one month period) - some more than others have. The two that seem to cause the problem more than the others are a G3 Beige 266 MHz and a G3 Blue & While 350 MHz. The other two are both G4s (450 MHz and 766 MHz respectively) The Beige G3 is connected via a 3COM 10BaseT hub which is connected into the Nortel Switch (all speed settings and duplexes are correct and functioning normally). The other 3 are connected directly to the switch, as are the other 3 Macs on the network.

 

 

 

The problem only happens with these Macs. None of the PCs on the LAN have ever caused a problem, or have the other Macs.

 

 

 

As being device-related I don't think so. Most of the time the backups go flawlessly and speeds are excellent. As for possible SCSI problems here to I don't think so since I initially suspected a communication problem and ran extensive tests to validate connectivity, flow control and data integrity.

 

 

 

Looks like a Retrospect reinstall is in order. Any suggestions as to whether I should save the backup scripts files or should recreate all new ones?

 

 

 

Thanks for the suggestions AmyC and taking the time to respond.

 

 

 

M.

 

 

[fivespan]

Would you think it possible that a CLIENT could hose the SERVER? It is a SERVER and should be primarily secured against such possiblilities. All the dang thing is doing is a fancy file transfer! Isn't this just ANOTHER branch in the argument that Retrospect is 'fragile'?