On Wed, Dec 06, 2006 at 04:33:16PM -0600, Evan Harris wrote: > > Debian testing, SDLT 110/220, Intel P4 2.8Ghz 3gig RAM. Amanda 2.5.1p1-2. > > The holding disk is a dedicated PATA IDE drive (master) on its own > cable/bus (no slave). The tape drive is on its own SCSI bus (no other > devices). Bonnie tests on the IDE drive give roughly 20MB/sec, and I have > no trouble keeping the tape drive streaming using dd from the IDE drive to > the tape drive. Amanda tapetest speed on the tapedrive came in right at > 10MB/sec.
I have an SDLT 220 also, mine being set for high density but without HW compression, I specifically perform SW compression (client side though in this case the client==server). I am also peaking about 10MB/sec per the amdump report. I have to look at the tape specs... Sun online docs show a sustained transfer rate of 11 MB/Sec, so you and I are both doing pretty well in that dept. Tell me again why you feel your drive is shoe-shining ? Are the specs for your particular drive substantially different ? > I'm currently testing on a standalone SDLT drive first. But the final > config will be the same type of drive in an ADIC changer. > > Evan > > On Wed, 6 Dec 2006, Brian Cuttler wrote: > > >Evan, > > > >What OS, type of tape, type of drive, HW platform ? > > > >I'm unfamiliar with a parameter to do what your asking > >for for good measure, what version of Amanda ? > > > >Actually, how did you determine that a drive within a changer > >was shoe-shining ? What else shares the bus with the tape and > >with the amanda work area drive(s) ? > > > >On Wed, Dec 06, 2006 at 02:34:31PM -0600, Evan Harris wrote: > >> > >>I'm having a problem with my tape drive shoe-shining because the holding > >>disk can't keep up with the tape drive if it is also being written to by a > >>dumper. Without the extra disk seek overhead of dumpers writing to the > >>holding disk at the same time, the holding disk should be plenty fast > >>enough to keep the tape drive streaming. > >> > >>Is there any way I can force amanda to serialize the dumper/taper so that > >>they are never run concurrently? I've already set inparallel to 1, but > >>that only affects how many dumpers can run, not the taper. > >> > >>I've also tried increasing the tapebufs parameter to 8000 (256MiB) to see > >>if that would at least let the drive stay streaming for longer periods, > >>but > >>if it made any difference, it wasn't significant. What thresholds does > >>the > >>taper use to decide when the tapebufs are filled enough to start tape > >>motion? There doesn't seem to be any docs on that, or settings to > >>customize. > >> > >>I did get a suggestion that I should just leave the tape out of the drive, > >>let the dumpers fill the holding disk and then load the tape and run > >>amflush, but that doesn't really work when using a changer, plus the > >>holding disk isn't large enough for the total size of all the backups, > >>though it can fit them one-by-one. > >> > >>Seems like there should be a "speed" config option for holding disks like > >>there is for network interfaces and tape drives, so that amanda could test > >>to see if the holding disk can't handle dumpers using the holding disk at > >>the same time a taper is running. That seems like it'd solve the problem > >>nicely, and even seems to fit with the scheme amanda uses for network > >>interfaces. > >> > >>Thanks. > >> > >>Evan > >--- > > Brian R Cuttler [EMAIL PROTECTED] > > Computer Systems Support (v) 518 486-1697 > > Wadsworth Center (f) 518 473-6384 > > NYS Department of Health Help Desk 518 473-0773 > > --- Brian R Cuttler [EMAIL PROTECTED] Computer Systems Support (v) 518 486-1697 Wadsworth Center (f) 518 473-6384 NYS Department of Health Help Desk 518 473-0773
