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!|
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