* Chris Hoogendyk <hoogen...@bio.umass.edu> [20090612 11:46]: > > Jean-Francois Malouin wrote: >> Hi, >> >> Not really an Amanda question but I'll try anyway... >> >> I can't get better than ~60MiBs to LTO4 tape when using amtapetype. I >> tried 32k 1024k and 2048k, with and without hw compression enabled. >> Any hints? I've added some info below. I can provide more upon request. >> >> Note that tapeinfo reports hw compression off but amtapetype says it >> on. The changer web interface also tells me that the drive has >> hardware compression off too. Puzzling. >> > > Just an off-hand note, and I am not 100% sure it applies specifically to > LTO4, but ... > > There was a detailed discussion on the Bacula list last year which > concluded that a tape drive will respect the status of a particular tape > regardless of what your settings are that you have configured the drive > with. So, if you use a tape that was once written with hardware > compression, it will continue to run that way. > > Try a brand new tape and see if it behaves any differently.
I'll give that a try. > > I'm assuming, of course, that you have also assessed all your hardware > and software and concluded that it ought to be able to support a higher > throughput to the tape. Yes I did assume that. As I wrote to Dustin this host used to do better than that with LTO3s, in fact I could have 2 tapers running at the same time and get more than 60MiBs on *both* drives. But I want to rule that out and will try with a box that I know gets ~100MiBs with LTO4s. regards! jf > > >> *** >> >> ArcVault-48 with LTO4 Ultrium HP. HBA is a LSI U320 in a PCI-X 133Mhz >> slot. Host is a quad core Xeon running Debian/2.6.29.3-i686-64-smp >> with amanda-2.6.1p1. >> >> >> #> tapeinfo -f /dev/sg5 >> Product Type: Tape Drive >> Vendor ID: 'HP ' >> Product ID: 'Ultrium 4-SCSI ' >> Revision: 'W23H' >> Attached Changer: No >> SerialNumber: 'HU18443UTY' >> MinBlock:1 >> MaxBlock:16777215 >> SCSI ID: 5 >> SCSI LUN: 0 >> Ready: yes >> BufferedMode: yes >> Medium Type: Not Loaded >> Density Code: 0x46 >> BlockSize: 0 >> DataCompEnabled: no >> DataCompCapable: yes >> DataDeCompEnabled: yes >> CompType: 0x1 >> DeCompType: 0x1 >> BOP: yes >> Block Position: 0 >> >> #> ~amanda/sbin/amtapetype -f -b 1024k /dev/nst1 >> Applying heuristic check for compression. >> Wrote random (uncompressible) data at 60250145.5737705 bytes/sec >> Wrote fixed (compressible) data at 73505177.6 bytes/sec >> Compression: enabled >> Writing one file to fill the volume. >> Wrote 813618429952 bytes at 62054 kb/sec >> Writing smaller files (8135901184 bytes) to determine filemark. >> define tapetype unknown-tapetype { >> comment "Created by amtapetype; compression enabled" >> length 794549248 kbytes >> filemark 1996 kbytes >> speed 62054 kps >> blocksize 1024 kbytes >> } >> >> regards, >> jf >> >> > > -- > --------------- > > Chris Hoogendyk > > - > O__ ---- Systems Administrator > c/ /'_ --- Biology & Geology Departments > (*) \(*) -- 140 Morrill Science Center > ~~~~~~~~~~ - University of Massachusetts, Amherst > > <hoogen...@bio.umass.edu> > > --------------- > > Erdös 4 > -- <° >< Jean-François Malouin McConnell Brain Imaging Centre Systems/Network Administrator Montréal Neurological Institute 3801 Rue University, Suite WB219, Montréal, Québec, H3A 2B4, Canada