Will,
Thank you for your response.
Have you been using your LTO7 for long? What kind of performance have you seen? What previous tape
drives are you able to compare it to?
I had used AIT5 for several years and then transitioned to LTO6, which I have been using for a few
years. I was able to drive both of those close to their spec speeds. In both cases I was able to
turn off compression and get a tapetype definition that showed close to spec speeds.
I haven't got the LTO7 in production yet and have just been playing with it with amlabel and
amtapetype to see what it does. The numbers that amtapetype gives back are not reassuring, and I
notice in your definition that the speed is not up to spec. Theoretically, the LTO7 should be twice
as fast as the LTO6, but amtapetype is getting about half the speed of the LTO6 when it fills the
tape in your example.
I wonder how many other Amanda users have tried LTO7 and what their experiences
have been.
On 8/3/17 3:59 PM, Will Aoki wrote:
On Mon, Jul 31, 2017 at 04:37:37PM -0400, Chris Hoogendyk wrote:
Here is my latest attempt, working with a new, never been loaded, LTO7 tape. I
should note that I have a page in my server notebook from July 2014 showing
almost this exact sequence of commands when setting up my LTO6 library.
Bottom line is that tapeinfo tells me compression is off, it's a new tape, then
amtapetype tells me compression is on.
I wasn't able to get compression turned off on the LTO-7 drive in my Quantum
SuperLoader 3. I ended up deciding to leave compression on, as it didn't seem
to do any harm in my testing.
My drive:
Product Type: Tape Drive
Vendor ID: 'IBM '
Product ID: 'ULTRIUM-HH7 '
Revision: 'FA17'
Attached Changer API: No
SerialNumber: '10WT------'
MinBlock: 1
MaxBlock: 8388608
SCSI ID: 23
SCSI LUN: 0
Ready: yes
BufferedMode: yes
Medium Type: 0x78
Density Code: 0x5c
BlockSize: 0
DataCompEnabled: yes
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
My tapetype:
#Checking for FSF_AFTER_FILEMARK requirement
#Applying heuristic check for compression.
#Wrote random (uncompressible) data at 92327868.852459 bytes/sec
#Wrote fixed (compressible) data at 165647058.823529 bytes/sec
#Compression: enabled
#Writing one file to fill the volume.
#Wrote 6015744049152 bytes at 86102 kb/sec
#Writing smaller files (60157427712 bytes) to determine filemark.
define tapetype lto-7 {
# Couldn't seem to get compression disabled...
comment "Created by amtapetype; compression enabled"
length 5874750048 kbytes
filemark 12 kbytes
speed 86102 kps
blocksize 32 kbytes
part_size 200G
part_cache_type memory
part_cache_max_size 48G
}
--
---------------
Chris Hoogendyk
-
O__ ---- Systems Administrator
c/ /'_ --- Biology & Geosciences Departments
(*) \(*) -- 315 Morrill Science Center
~~~~~~~~~~ - University of Massachusetts, Amherst
<[email protected]>
---------------
Erdös 4
