Kasper Edwards <[EMAIL PROTECTED]> writes: > Hi, > > Im using amanda on a linux box with an old SONY-SDT5000 DDDS2 drive. > Everything works like a charm - I have actually restored some files ;) > > The question: Is it recommended to use hardware compression or should I > leave it off? When I first configured the thing a few month ago I left > compression ON, but now im not sure if it actually were a good idea.
Kasper, I'd summarize the three choices as follows: Hardware compression: + no CPU overhead + high restore speed + more data/tape - effective tape size unknown - no data reread on other drive types Sofware compression: - CPU overhead - slow restore speed (unzipping the whole "disk" to get at one file) + more data/tape + effective tape size known to amanda + data reread no compression + no CPU overhead + fast restore speed - less data/tape + effective tape size known + data reread Given server hardware more recent than the tape drive you should be able to do software compression faster than the tape can write/read. You could change config once a day and use amanda (e. g. amplot) as a benchmark for all components involved. Please don't use hardware and software compression at the same time. HW compression enlarges the data in this case. HTH, Johannes Nie�
