>>>>> "AL" == Arno Lehmann <[EMAIL PROTECTED]> writes:
Hi! AL> On 10/10/2006 9:59 AM, Anders Boström wrote: >>>>>>> "KS" == Kern Sibbald writes: >> >> KS> From the statistics you show, the backup does not appear slow to KS> me. The reason you might think it is slow is because you are KS> comparing apples and oranges. >> KS> On the one hand, you measure the time to to a non-compressed tar KS> on a local machine sending the output down an extremely hi-speed >> bit bucket. >> KS> On the other hand, you measure the time of Bacula using KS> compression sending real data to another process via TCP/IP (even KS> though it might be on the same machine). >> KS> To do a better comparison, you could run tar including the z KS> option so that it does compression. In addition, you should send KS> the output of tar across the network and write it to either a file KS> or a tape (whatever Bacula is using). >> >> You don't seem to have seen my data, so I state it again: >> >> bacula backup without SW compression: 1 hour 45 mins 2 secs >> bacula backup with SW compression: 2 hours 42 mins 11 secs >> local tar on the fileserver*: 53 mins 3 secs >> >> * time /bin/sh -c "tar cf - directory | cat >/dev/null" AL> Well, your tar does not create disk I/O for the data it "writes". >> bacula is ~2 times slower than the local tar without SW >> compression. And, as stated already, the network isn't the limitation >> (no TCP retransmission), neither is the backup-server (CPU and disc is >> >>> 98% idle during backup). AL> Still the network is being used and that always involves latencies, AL> syncronization times, etc. Yes, and that might be the problem. But if it is about latencies and/or synchronization, then it is a bacula performance problem! Is bacula limited in performance due to high latency? (Not that we have that problem, but anyway...) Is bacula limited in performance due to synchronization? >> But, as you point out, the tar should be faster. It doesn't need to >> write to net. However, not 2 times faster. The net-load is ~1% (10 >> Mbit/s on a GE-network), and *should* not affect the performance in >> this case. AL> *Should* is not very helpful here... instead, send the tar output AL> through a netcat to the backup server and write it to disk. For example. But we have two scenarios here: 1. Bacula is affected by a very low network load. 2. Bacula isn't affected by a very low network load. If (1) is true, why??? / Anders ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
