On Fri, Apr 22, 2016 at 5:21 AM, Paul Groves <paul.groves.787@gmail.com> wrote:
Hi,
I am struggling to back up using LTO hardware compression in linux (the drives and tapes have been tried in windows and work as expected).
I am using Hp Storageworks 232 lto1 / 448 lto2 / 920 lto3 and 3000 lto5 and a HP DAT72 drive on Leap 42.1 all with the same problem
I have tried mt with the datcompression option and it says it is on for all my drives I have tried mtst with the compression option which does nothing at all with no output
Also my drives are /dev/st0 st1 st2 and st3 also listed as /dev/st*1 /dev/st*m and /dev/st*a
A quick google say these are different modes. What are these modes? Is one to enable the hardware compression?
I am able to write to tapes and restore using tar -cvWf /dev/st* /srv/mydata/something but it does not even allow the native tape capacity (e.g. lto3 is native 400gb and I can't even fit 350GB on this tape (even after mt -f /dev/st3 erase 1)
I have gone through HP's manual and there is no information on hardware compression.
Does anyone know how to use hardware compression on LTO drives in linux?
Thanks
Paul
Very strange. I've used LTO-4, but I've never used LTO-5 (I no longer use tape routinely.) I hope the below isn't too out of date: As you say there are 4 modes: /dev/st0 /dev/st0l (zero ell) /dev/st0m /dev/st0a The above are in order (1, 2 ,3, 4). The definition of the modes isn't permanently defined so some docs tend to just say they are modes and leave it to you to figure what they do. If you care, you should override them with your own definitions. To override what the modes are, I think you need to install mt-st (or mt_st). Then copy /usr/share/doc/packages/mt_st/stinit.def.examples to /etc/stinit.def and edit appropriately. man stinit will tell you the options you can use in the file. Here's a example LTO5 entry from debian: https://wiki.debian.org/StinitDef#LTO5 You will need some data about the drive. From the example def file: # The manufacturer, model, and revision strings can be obtained, # from the file /proc/scsi/scsi (cat /proc/scsi/scsi). I don't recall if you have to add a call stinit during bootup, or if it is automatic. Regardless, for testing you can invoke it manually. Hope that helps. Greg -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org