* William Taylor <[email protected]> [20100222 17:56]: > > On Feb 22, 2010, at 1:33 PM, Jean-Francois Malouin wrote: > > > I use tape_splitsize=10GB but I don't think this is relevant in terms > > of performance. blocksize=2048MB but again my tests never showed > > significant differences in the range [512MB-2048MB] > > Are you using split_diskbuffer or fallback_splitsize? > If fallback_splitsize what size do you use 10GB?
Same but read remark: tape_splitsize 10Gb fallback_splitsize 10Gb but my experience is going in port-write mode just doesn't cut it. I typically get ~25-30MBps to the tape, ie shoe shining. Never bothered to know why since I always have a holddisk available. > > My backups are already local on disk (/dev/sdb). Does it make sense to define > a holding disk (/dev/md0 striped 14 disks) and have amanda moving them in > chunks to > it ? There will be some contention for sure if both are on the same controller/IO path. Why don't you test it? Sucking up 100MBps sustain or more from a raid will be hard to achieve unless you throw a lot of $$$ to it which is why you want a well tuned striped staging area between your data and tape drive. You can then also starts playing with the flush-threshold* variables and taperflush to stuff your holddisk up to a certain level before writing to tape. Very cool new addition to amanda. Just a suggestion though. regards, jf
