Greg Troxel schrieb: > Amanda reports a wide range of tape write speeds during actual backups > and flushing, and I can't make sense of them - some of them seem too > high by a factor of 8.
You mean the output of amstatus? No, there are no tape rates afaik, so you mean the report email? > Doing dd of a 8.5G file (2G ram, dumped several days ago, so could not > possibly be in the cache) to /dev/null gets me 42.3 MB/s. The raw drive > gets me 67.8 MB/s. > > This was all without another process writing dumps. > > So for LTO-2, regular drives seem just barely ok. For LTO-4 I wouldn't > be so sure, as I think that needs 80 MB/s minimum. My main problem seems to be the concurrent writes of the dumpers versus the read-processes of the taper ... :-( Right now I have a RAID0 over two LVM-LVs which still doesn't perform good enough. I will repartition the drives to get two plain Linux-raid-partitions without that additional LVM-layer I have right now (it was simpler to try it this way first ...). Maybe that helps a bit. An additional fact is that these two disks also contain DLEs to be dumped so with amdump I get some traffic between LVs ... which also decreases performance
