On Sun, 2005-11-20 at 19:36 +0100, Paul Bijnens wrote: > > Turns out the problem was the iptables packet filter on the amanda > > client. iptables has a timeout for idle TCP connections that was > > breaking the connection to the server before the initial estimate of the > > backup size was done (because it took so long to go through the huge > > DLE). > > > > The solution is to decrease the time between keepalive packets: > > > > 'echo 90 > /proc/sys/net/ipv4/tcp_keepalive_time'
> I don't think this will help, because the estimates are exchanged > using UDP traffic. > > The backups are send over a TCP connection, but there you'll rarely > need to increase some timeout. > > Are you realy 100% sure that it was this setting that made your > backups succeed? The setting did it, but my understanding of why is wrong. As I said to Paul off list, I put the default value back and watched last night's backup. The three ~12GB estimates came in, and the timeouts happened during the data transfers (Connection reset by peer). I don't understand this. iptables times out and breaks a TCP connection on time, even if 100% of the bandwidth of that connection is being used?? I doubt it I set the timeout to 90 and reran a backup by hand. The data transfers are working. In other words, increasing iptables' TCP timeout seems to be necessary for amanda backups of huge DLEs, but I don't understand why. ... It says in the amanda dox ( http://www.amanda.org/docs/portusage.html ) > AMANDA also uses TCP connections for transmitting the backup image, > messages and (optionally) the index list from a client back to the > dumper process on the tape server. A process called sendbackup is > started by amandad on the client. It creates two (or three, if > indexing is enabled) TCP sockets and sends their port numbers back to > dumper in a UDP message. Then dumper creates and binds TCP sockets on > its side and connects to the waiting sendbackup. This sounds a lot like FTP to me. Maybe it's the messages connection that's timing out. -- Glenn English [EMAIL PROTECTED] GPG ID: D0D7FF20 -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
