Me again! My problem is that I get sub-acceptable performance from SSH2 when I use backups over it. On Atro's advice, I rebuilt SSH with -O2 for optimization and repeated my previous trial backups. In fact, I've repeated the following set of trials several times and the results are quite reliable. The -O2 did make a improvement of some 15%, and the use of blowfish made some improvement as well. Those trials are not reported here. For these trials, I made the situation nearly identical to our actual backup situation: a backup is run from a client to the server via bru (bru is a replacement for tar). The only deviation from the real-life situation is that the remote command used "cat > filename" instead of writing to the tape drive. On the server 'tapeclient', I ran the following commands: bru -cf - /usr/local | rsh tapeserv -l tapeuser "cat > foo-rsh.bru" bru -cf - /usr/local | ssh tapeserv -c none -l tapeuser "cat > foo-ssh1.bru" bru -cf - /usr/local | ssh tapeserv -c blowfish -l tapeuser "cat > foo-ssh2.bru" The size of the brufile was 111 MB on some trials, 96 MB for others. This is because some trials were more of an afterthought. RSH 111 MB / 3.75 min = 29.6 MB/min = 34.6 min/GB SSH cipher=blowfish compression=yes 111 MB / 10.5 min = 10.6 MB/min = 96.6 min/GB SSH cipher=blowfish compression=no 96 MB / 8.8 min = 10.9 MB/min = 93.9 min/GB SSH cipher=none compression=yes 111 MB / 8.3 min = 13.4 MB/min = 76.4 min/GB SSH cipher=none compression=no 96 MB / 7.3 min = 13.1 MB/min = 77.9 min/GB Notably, the compression made a visible but insignificant difference, about 3%. RSH's performance of 34 min/GB is the same as what we're currently getting when we use RSH to backup to the tape drive during late-night non-peak hours. Also, neither the client nor the server were under any significant load during the backups - load average and CPU usage were quite nominal. As such, the following factors are unlikely to be significant causes of this poor performance: - network load - resource load on the server - using cat>file instead of the tape drive Any ideas? -- Gregor Mosheh [EMAIL PROTECTED] Systems Admin, Humboldt Internet 707.825.4638
