After research, I started using 512k blocks, 3 years ago, for LTO5 tapes. For LTO7 I might have to research even more, but certainly 512k or bigger.
Debra Baddorf Fermilab > On Jan 11, 2018, at 2:09 PM, Jean-Louis Martineau <[email protected]> > wrote: > > Luc, > > amtapetype use speed heuristic to detect if the drive is in compressed > mode, it might not be good for newer drives. > > Why you didn't post the complete amtapetype output? I can't tell you why > the heuristic is bad without those numbers. > > The default block size of 32k was good 15 years ago, but it is really > bad for new drives. You should really think about increasing it a lot. > > Jean-Louis > > On 11/01/18 02:56 PM, Luc Lalonde wrote: > > I sent the wrong output in the last email.... Here's the correct > > 'tapeinfo': > > > > Product Type: Tape Drive > > Vendor ID: 'IBM ' > > Product ID: 'ULTRIUM-HH7 ' > > Revision: 'G9Q1' > > Attached Changer API: No > > SerialNumber: '123456789A' > > MinBlock: 1 > > MaxBlock: 8388608 > > SCSI ID: 4 > > SCSI LUN: 0 > > Ready: yes > > BufferedMode: yes > > Medium Type: 0x78 > > Density Code: 0x5c > > BlockSize: 32768 > > DataCompEnabled: no > > DataCompCapable: yes > > DataDeCompEnabled: yes > > CompType: 0xff > > DeCompType: 0xff > > BOP: yes > > Block Position: 0 > > Partition 0 Remaining Kbytes: -1 > > Partition 0 Size in Kbytes: -1 > > ActivePartition: 0 > > EarlyWarningSize: 0 > > NumPartitions: 0 > > MaxPartitions: 3 > > > > Further, here's my '/etc/stinit.def': > > > > manufacturer="IBM" model = "ULTRIUM-HH7" { > > scsi2logical=1 > > can-bsr=1 > > auto-lock=1 > > two-fms=0 > > drive-buffering=1 > > buffer-writes > > read-ahead=1 > > async-writes=1 > > can-partitions=1 > > fast-mteom=0 > > sysv=1 > > timeout=180 > > long-timeout=14400 > > mode1 blocksize=32768 compression=1 > > mode2 blocksize=32768 compression=0 > > mode3 disabled=1 > > mode4 disabled=1 > > > > Sorry, about that! > > > > On 2018-01-11 02:43 PM, Luc Lalonde wrote: > >> Hello Folks, > >> > >> I'm wondering if there's a bug with 'Amtapetype' (version 3.5.1). > >> > >> We're migrating from LTO5 to LTO7 and I'm getting strange results > >> when I run 'amtapetype'. > >> > >> Here's what I get after roughly 35 hours: > >> > >> define tapetype LTO7 { > >> comment "Created by amtapetype; compression enabled" > >> length 5874932832 kbytes > >> filemark 1813 kbytes > >> speed 118310 kps > >> blocksize 32 kbytes > >> } > >> > >> Why is it saying that it can write roughly 6Tb if it's supposedly > >> hardware compressed? LTO7 is supposed to give a compression ration > >> of 2.5 to 1. > >> > >> I've disabled compression... Here's the ouptut of 'tapeinfo: > >> > >> [root@ulysses ~]# tapeinfo -f /dev/sg12 > >> Product Type: Tape Drive > >> Vendor ID: 'IBM ' > >> Product ID: 'ULTRIUM-HH7 ' > >> Revision: 'G9Q1' > >> Attached Changer API: No > >> SerialNumber: '123456789A' > >> MinBlock: 1 > >> MaxBlock: 8388608 > >> SCSI ID: 4 > >> SCSI LUN: 0 > >> Ready: yes > >> BufferedMode: yes > >> Medium Type: 0x78 > >> Density Code: 0x5c > >> BlockSize: 32768 > >> DataCompEnabled: yes > >> DataCompCapable: yes > >> DataDeCompEnabled: yes > >> CompType: 0xff > >> DeCompType: 0xff > >> Block Position: 2 > >> Partition 0 Remaining Kbytes: -1 > >> Partition 0 Size in Kbytes: -1 > >> ActivePartition: 0 > >> EarlyWarningSize: 0 > >> NumPartitions: 0 > >> MaxPartitions: 3 > >> > >> Am I missing something? > >> > >> Thanks!| > >> > > > > > Disclaimer > > This message is the property of CARBONITE, INC. and may contain confidential > or privileged information. > > If this message has been delivered to you by mistake, then do not copy or > deliver this message to anyone. Instead, destroy it and notify me by reply > e-mail. >
