Hello! Jon H. LaBadie wrote:
> On Mon, Nov 04, 2002 at 03:04:27PM +0100, Patrick M. Hausen wrote: > > > > So my question is: does a holding-disk speed up this process? I mean, > > Amanda will start a dumper on the filesystem that starts filling > > the holding-disk. At the same time (?) a taper will start wrtiting > > the holding-disk's contents to tape. Now imagine the dumper getting > > to slow for the tape ... the holding-disk won't be filled quick > > enough either. Then there's a lot of seeks on the holding-disk > > itself, if it's read and written at the same time. > > > > Or is the mental picture I have about Amanda's operation incorrect? > > yes, incorrect. > > nothing goes from holding disk to tape unless the dump to holding disk > has finished. Then it goes like cat'ting or dd'ing to tape. Small > likelyhood of too slow for tape. Aggreed - cat/dd >/dev/tape will surely be fast enough. But I need a holding disk at least as large as my largest FS to dump? So if I have one 170 GB RAID I need one 170 GB holding disk? The customer won't like that ;-) Or is this what the chunksize parameter is for - taper will start when the first chunk is completely written to the holding disk? In this case I'm sure a holding disk will speed up things quite a bit even in my "pathological" case of only one big FS. A little bit of tape stop-and-go between chunks won't hurt as much as the current configuration does. Thanks, Patrick M. Hausen Technical Director -- punkt.de GmbH Internet - Dienstleistungen - Beratung Scheffelstr. 17 a Tel. 0721 9109 -0 Fax: -100 76135 Karlsruhe http://punkt.de
