mhVTL with Rotating Hard Disk

[james2k2]

Hi All,

I've been thinking about this for a while now since getting it all up and running.

Basically, I am wanting to treat external USB drives as a separate tape and using them on a rotational basis for offsite storage. I am using Win2k8 R2 with Microsoft DPM 2010 and using the default directories on the computers internal hard disk this works for the most part.

Ultimately, I would imagine I could have this configuration:
1 Library -> 1 Drive -> 8 Tapes

Each Tape is mapped to a Hard Disk and I would imagine with a 3rd party tool, I can get it to identify the hard disk and auto-mount the correct virtual tape.

Is this something that's possible?

[nia]

Check out this post, perhaps pointing to your rotating tapes via sym links is the only way :

http://mhvtl-a-linux-virtual-tape-library.966029.n3.nabble.com/Multiple-mount-points-td2746184.html#a2747089

[james2k2]

Thanks nia!

I had totally forgotten about symlinks.

I have thought of another way however, but I think this only works with the way DPM seems to manage tapes.

Ultimately, I'm looking for a 'swap drive and not worry' approach so for example, we have monday to friday usb disks and we manually change the disk each day. I'm using exFAT due to permission issues I had using NTFS, and by default any exFAT disk is always mounted as /media/exfat, so I've configured my library to write data there. This works, data is written. However I'm now having issues with my configuration.

I firstly tried with a standalone drive configuration, but I can't see in the GUI how to do a mount, so I sacked that idea. Now I've tried to configure a changer (HP MSL6000) and single drive (HP Ultrium 3-SCSI) and 2 tapes. Now I thought the idea was that on a tape load request from DPM, it would then automatically take one of the available tapes from the slots and mount it, but the drive element isn't showing up in the library, just 2 slots with tapes in them.

If I use mtx and ask for info on Changer0 I get:

C:\mtx>mtx -f Changer0 status
  Storage Changer Changer0:1 Drives, 3 Slots ( 1 Import/Export )
Data Transfer Element 0:Empty
      Storage Element 1:Full :VolumeTag=HPS001L3
      Storage Element 2:Full :VolumeTag=HPS002L3
      Storage Element 3 IMPORT/EXPORT:Empty

and Tape0:

C:\mtx>mtx -f Tape0 status
mtx: Request Sense: Long Report=yes
mtx: Request Sense: Valid Residual=yes
mtx: Request Sense: Error Code=70 (Current)
mtx: Request Sense: Sense Key=Illegal Request
mtx: Request Sense: FileMark=no
mtx: Request Sense: EOM=no
mtx: Request Sense: ILI=no
mtx: Request Sense: Residual = 00 00 00 00
mtx: Request Sense: Additional Sense Code = 20
mtx: Request Sense: Additional Sense Qualifier = 00
mtx: Request Sense: BPV=no
mtx: Request Sense: Error in CDB=no
mtx: Request Sense: SKSV=no
READ ELEMENT STATUS Command Failed

Kind Regards,
James

[Mark Harvey]

mtx is only for medium changers

use 'mt' cmd for tape devices

[james2k2]

Hi Mark,

Thanks for the tip. I used 'tapeinfo -f Tape0' in the end, and that provided all the details. I can see from the report that the configuration is definetely working, it's just for some reason DPM can't see the Drive, and when it can see it, it thinks it's a separate entity.

C:\mtx>tapeinfo -f Tape0
Product Type: Tape Drive
Vendor ID: 'HP      '
Product ID: 'Ultrium 3-SCSI  '
Revision: 'N11G'
Attached Changer API: No
SerialNumber: '80000011  '
MinBlock: 4
MaxBlock: 2097152
Ready: yes
BufferedMode: yes
Medium Type: Not Loaded
Density Code: 0x44
BlockSize: 0
DataCompEnabled: yes
DataCompCapable: yes
DataDeCompEnabled: yes
CompType: 0xffffffff
DeCompType: 0xffffffff
BOP: yes
Block Position: 0
Partition 0 Remaining Kbytes: 50000
Partition 0 Size in Kbytes: 50000
ActivePartition: 0
EarlyWarningSize: 0

Thanks again,
James