* Jon LaBadie <[EMAIL PROTECTED]> [20070802 13:23]: > On Thu, Aug 02, 2007 at 12:03:35PM -0400, Jean-Francois Malouin wrote: > > > > My bad, replying to myself... > > Here's the outpout of 2 simultaneous running dd's on non-compressing > > tape devices daisy-chained to the same scsi hba (LSI U320 PCI-X): > > > > grumpy:~# time dd if=/dev/zero of=/dev/nst0 bs=32k > > dd: writing `/dev/nst0': No space left on device > > 12424636+0 records in > > 12424635+0 records out > > 407130439680 bytes (407 GB) copied, 7003.39 seconds, 58.1 MB/s > > > > real 116m43.419s > > user 0m11.317s > > sys 3m7.260s > > > > grumpy:~# time dd if=/dev/zero of=/dev/nst1 bs=32k > > dd: writing `/dev/nst1': No space left on device > > 12424636+0 records in > > 12424635+0 records out > > 407130439680 bytes (407 GB) copied, 7002.45 seconds, 58.1 MB/s > > > > real 116m42.477s > > user 0m11.677s > > sys 3m6.480s > > > > Looks good to me. > > Not sure why amtapetype tops at 40MBs. > > > > Size is less than amtapetype: Earlier you said amtapetype > gave ~386GB. dd's decimal 407 gig is 379GB binary.
Of course you're right! And I made the same mistake twice: actually the tapetype length was 386048 mbytes which is in fact 377GB binary *not* 386GB decimal as I posted on the first post of this thread. > > As to speed, dd is only using the scsi controller for > writing, does amtapetype use it to also read its data? Not sure how it works. I guess I'll have to get dirty and look at the source... jf > > jl > -- > Jon H. LaBadie [EMAIL PROTECTED] > JG Computing > 4455 Province Line Road (609) 252-0159 > Princeton, NJ 08540-4322 (609) 683-7220 (fax) -- <° ><