On Wed, 2002-07-03 at 10:47, Scaglione Ermanno wrote: > thanks but I found the real problem: there is a cisco router doing NAT > between the amanda server and the two server. I found that it had a nat udp > timeout of 6 minutes (CISCO default). What happens is that amanda gets the > estimates from the first server that answers and starts the backup on that > server, then the link becomes too busy, the UDP connection with the second > server times out on the router and the second backup doesn't work ...... > Well we could consider this an amanda bug maybe, the problem is that amanda > doesn't do keepalive while sendsize runs, and sendsize itself doesn't do > keepalive. I have been told that most CISCO routers doing NAT have this 6 > minutes nat udp timeout thus if the estimate takes more than 6 minutes the > backup will probably fails if there is such a router in between ..... > > ----- Original Message ----- > From: "Chris Marble" <[EMAIL PROTECTED]> > To: "Scaglione Ermanno" <[EMAIL PROTECTED]> > Sent: Wednesday, July 03, 2002 4:39 AM > Subject: Re: syncronize backups > > > > Scaglione Ermanno wrote: > > > > > > I have a strange problem with amanda, I am backing up 6 servers with the > > > same disklist and 2 of them alternatively fails with a timeout in > sendsize. > > > Server A works for a couple of days and server B doesn't in the same > days, > > > then server B works and server A doesn't. I suppose the reason is that > both > > > server are behind a slow link. How can I tell Amanda not to backup > > > simultaneously the two servers using 1 disklist? > > > > Hmm, I was going to tell you to lie to Amanda and tell it that all the > disks > > are on the same spindle. But then I realized that the spindle parameter > is > > on a per-machine basis. You could set an earlier starttime for those > servers and > > set inparallel to 1 just for a while. > > -- > > [EMAIL PROTECTED] - HMC UNIX Systems Manager > > > >
Interesting. Do I understand your suggestion correctly to imply that keepalive be done on udp sockets. If so, might I suggest that this is not the solution. Its been several years since I programmed tcp and udp clients and servers, but if memory serves me correctly, keepalive is only available in the tcp-family of protocols. Keepalive was intended to maintain an otherwise idle connection for some period of time. Udp by definition is not a connected protocol and such an option would be meaningless for it.
