I setup a test system with an old LTO4 stand alone drive.
Our config right now uses a lot of client side compression (AWS instances, bandwidth expensive CPU cheap)
But was testing using the autoxflate-sd plugin to decompress as part of a VirtualFull to write the archive tapes and just use tape drive hardware compression. not really required but still learning the ecosystem.
I have tested Auto Inflate = in / out / both
None appear to create any extra entries in the job log, and the data volumes on the tape and the job appear the same, and the speed from the spool space and the tape drive with tapestat 1 are the same.
The data are compressible.
Also the compression counter for the tape using
sg_logs -a /dev/nst0
Return a write compression of 101 .
I’m pretty sure compression is on on the drive, or at lest I would expect the job size to go up vs the on tape size for this compressible data ( a lot of text ).
Thoughts? Device config below.
Device {
Name = T-LTO4
Autochanger = no
Drive Index = 0
Media Type = LTO4
Archive Device = /dev/nst0
Device Type = Tape
Maximum File Size = 20000000000 # 20 GB
Spool Directory = /mnt/spool/Q-LTO4
Maximum Job Spool Size = 80000000000
Maximum Spool Size = 160000000000
Drive Crypto Enabled = Yes
Query Crypto Status = yes
Maximum Concurrent Jobs = 1
Auto Inflate = both
}
Brock Palen
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