Issues with QuikStation/Tape Emulation on Debian 12 as a Veeam Tape Server: I/O error and “incorrect block size”

[j.suenram@it-ngo.com]

Edit: Veeam Support - Case # 07615390 - Tape Job failing

Summary of the Problem:
1. Setup
• I’m using an Overland Tandberg QuikStation 8 (tape/RDX emulation) with Veeam Backup & Replication.
• A Windows Server 2019 as the tape server (iSCSI connected to the QuikStation) works perfectly for creating and writing tapes – no errors.
• Under Debian 12 (and similarly under Rocky Linux), I have configured the iSCSI tape access for Veeam.
2. Observations on Debian 12
• Veeam successfully detects the emulated tape library: the library and tape drives appear in Veeam.
• Verification and reading operations on existing backups/tapes complete successfully.
• Writing/backing up to tape, however, fails with:
• “The request could not be performed because of an I/O device error. Failed to enable hardware compression.” (as reported by Veeam)
• In the Debian system log (journalctl), there is:
• “kernel st 9:0:0:0: st1 incorrect block size.”
3. Additional Technical Details
• lsscsi -g shows, among others:

Code: Select all

[8:0:0:0] tape    HP Ultrium 3-SCSI D237 /dev/st0  /dev/sg2
[9:0:0:0] tape    HP Ultrium 3-SCSI D237 /dev/st1  /dev/sg3
[7:0:0:0] mediumx EXABYTE MAGNUM 224     V290      /dev/sch0 /dev/sg4

Veeam appears to use /dev/sg2 and /dev/sg3 for the drives (Generic SCSI), but Linux reports “incorrect block size” when writing.
• Manually switching the tape block size (e.g., via mt -f /dev/nstX setblk 0) was attempted, but the “Failed to enable hardware compression” error in Veeam persisted.

Background & Assumptions
• Under Windows, neither hardware compression nor block size presents any issues.
• Under Linux, the attempt to enable hardware compression (SCSI Mode Sense/Select) triggers an I/O error or “illegal request”, possibly indicating an incompatibility or firmware issue in the QuikStation emulation.
• The Linux tape subsystem (st driver) may interpret the emulation differently, conflicting with the requested compression/block size parameters.
5. Questions for the Forum
1. Has anyone encountered similar cases where Debian/Linux combined with a virtual tape emulation (QuikStation or otherwise) experiences issues when enabling/disabling hardware compression?
2. Are there registry/config settings in Veeam that completely prevent hardware compression from being attempted? (Hardware compression is already disabled at the media pool level, but the error still appears.)
3. Has anyone found a workaround (e.g., patches, firmware updates, specific iSCSI/tape parameters) to resolve this issue?

Thank you in advance for any help or suggestions!

[david.domask]

Hi j.suenram@it-ngo,com,

Thanks for sharing the case number and sorry to hear about the challenges.

We do have a Veeam Ready entry for the QuikStations, but it was checked on Veeam v10 last and with Windows Tape Server, so I'm not sure that it's been tested with Linux.

Out of curiosity, is the Quikstation able to emulate any other library type? Just I can remember at least for other VTLs, the emulation was a bit "iffy" and it's possible another emulated library/drive may work better.

Please continue with Support on this case, as situation is not expected. "Failed to enable hardware compression" is a bit unusual for me as I wonder if it's failing to tell the drive "not" to use compression during the writes, as I saw similar issues on emulated tape libraries before (this was with very early quadtor vtl version, but maybe similar)

[j.suenram@it-ngo.com]

Thanks for reply.
The Quikstation has 2 different modes for emulation. We tested with both, both have the same behavior. Windows OK. Linux same error.