Can't mount LTFS tape with HBA in Thunderbolt PCIe Enclosure

[kdev231u98r]

Describe the bug
I have written several LTO-7 tapes with LTFS, never had a major problem with old QLogic 8GB FC HBA (HP part number) directly connected to the mainboard.

For a portable solution, I put an HBA into a Thunderbolt 3 expansion enclosure. Thunderbolt works, HBA and tape drive are recognized, but I can't mount tapes.

I have tested it via Thunderbolt on several devices with Ubuntu, it is always the same error messages.

Tapes were formatted weeks ago with mkltfs -d ... without further arguments and written with data and unmounted cleanly.

Does anyone have any idea what the problem could be?

To Reproduce

# sudo ltfs -o device_list
11ab LTFS14000I LTFS starting, LTFS version 2.5.0.0 (Prelim), log level 2.
11ab LTFS14058I LTFS Format Specification version 2.4.0.
11ab LTFS14104I Launched by "ltfs -o device_list".
11ab LTFS14105I This binary is built for Linux (x86_64).
11ab LTFS14106I GCC version is 14.2.0.
11ab LTFS17087I Kernel version: Linux version 6.14.0-15-generic (buildd@lcy02-amd64-022) (x86_64-linux-gnu-gcc-14 (Ubuntu 14.2.0-19ubuntu2) 14.2.0, GNU ld (GNU Binutils for Ubuntu) 2.44) #15-Ubuntu SMP PREEMPT_DYNAMIC Sun Apr  6 15:05:05 UTC 2025 i386.
11ab LTFS17089I Distribution: PRETTY_NAME="Ubuntu 25.04".
11ab LTFS17089I Distribution: DISTRIB_ID=Ubuntu.
11ab LTFS17085I Plugin: Loading "sg" tape backend.
Tape Device list:.
Device Name = /dev/sg1 (2.0.0.0), Vendor ID = IBM     , Product ID = ULTRIUM-TD7     , Serial Number = F002------, Product Name =[ULTRIUM-TD7].

# sudo ltfs -o devname=/dev/sg1 /mnt/ltfs
138c LTFS14000I LTFS starting, LTFS version 2.5.0.0 (Prelim), log level 2.
138c LTFS14058I LTFS Format Specification version 2.4.0.
138c LTFS14104I Launched by "ltfs -o devname=/dev/sg1 /mnt/ltfs".
138c LTFS14105I This binary is built for Linux (x86_64).
138c LTFS14106I GCC version is 14.2.0.
138c LTFS17087I Kernel version: Linux version 6.14.0-15-generic (buildd@lcy02-amd64-022) (x86_64-linux-gnu-gcc-14 (Ubuntu 14.2.0-19ubuntu2) 14.2.0, GNU ld (GNU Binutils for Ubuntu) 2.44) #15-Ubuntu SMP PREEMPT_DYNAMIC Sun Apr  6 15:05:05 UTC 2025 i386.
138c LTFS17089I Distribution: PRETTY_NAME="Ubuntu 25.04".
138c LTFS17089I Distribution: DISTRIB_ID=Ubuntu.
138c LTFS14063I Sync type is "time", Sync time is 300 sec.
138c LTFS17085I Plugin: Loading "sg" tape backend.
138c LTFS17085I Plugin: Loading "unified" iosched backend.
138c LTFS14095I Set the tape device write-anywhere mode to avoid cartridge ejection.
138c LTFS30209I Opening a device through sg-ibmtape driver (/dev/sg1).
138c LTFS30250I Opened the SCSI tape device 2.0.0.0 (/dev/sg1).
138c LTFS30207I Vendor ID is IBM     .
138c LTFS30208I Product ID is ULTRIUM-TD7     .
138c LTFS30214I Firmware revision is Q386.
138c LTFS30215I Drive serial is F002------.
138c LTFS30285I The reserved buffer size of /dev/sg1 is 262144.
138c LTFS30205I RSOC (0xa3) returns -20603.
138c LTFS30263I RSOC returns Power On, Reset, or Bus Device Reset Occurred (-20603) /dev/sg1.
138c LTFS30262I Forcing drive dump.
138c LTFS39802W Unknown SCSI OP code 0x1d, use default timeout.
138c LTFS30253I Saving drive dump to /tmp/ltfs_F002------_2025_0607_181437_f.dmp.
138c LTFS39802W Unknown SCSI OP code 0x3c, use default timeout.
138c LTFS39802W Unknown SCSI OP code 0x3c, use default timeout.
138c LTFS30200I Failed to execute SG_IO ioctl, opcode = 3c (22).
138c LTFS30263I READ_BUFFER returns ioctl error (-21700) /dev/sg1.
138c LTFS30258W Cannot retrieve drive dump: failed to read buffer (-21700).
138c LTFS30294I Setting up timeout values from vendor and device.
138c LTFS17160I Maximum device block size is 1048576.
138c LTFS11330I Loading cartridge.
138c LTFS30252I Logical block protection is disabled.
138c LTFS11332I Load successful.
138c LTFS17157I Changing the drive setting to write-anywhere mode.
138c LTFS11005I Mounting the volume from device.
138c LTFS30252I Logical block protection is disabled.
138c LTFS30200I Failed to execute SG_IO ioctl, opcode = 08 (22).
138c LTFS30263I READ returns ioctl error (-21700) /dev/sg1.
138c LTFS12049E Cannot read: backend call failed (-21700).
138c LTFS17039E XML parser: failed to read a block from the medium (-21700).
138c LTFS17037E XML parser: failed to read from XML stream.
138c LTFS17273E XML parser: Detected an I/O error on reading an index from the tape (-21700).
138c LTFS17016E Cannot parse index direct from medium (-21700).
138c LTFS11194W Cannot read index: failed to read and parse XML data (-21700).
138c LTFS11024E Cannot mount volume: read index failed on the index partition.
138c LTFS14013E Cannot mount the volume from device.
138c LTFS30252I Logical block protection is disabled.

2e:00.0 Fibre Channel: QLogic Corp. ISP2532-based 8Gb Fibre Channel to PCI Express HBA (rev 02)
	Subsystem: Hewlett-Packard Company StorageWorks 81Q
	Flags: bus master, fast devsel, latency 0, IRQ 17, IOMMU group 17
	I/O ports at 6000 [disabled] [size=256]
	Memory at 6a140000 (64-bit, non-prefetchable) [size=16K]
	Memory at 6a000000 (64-bit, non-prefetchable) [size=1M]
	Expansion ROM at 6a100000 [virtual] [disabled] [size=256K]
	Capabilities: [44] Power Management version 3
	Capabilities: [4c] Express Endpoint, IntMsgNum 0
	Capabilities: [88] MSI: Enable- Count=1/32 Maskable- 64bit+
	Capabilities: [98] Vital Product Data
	Capabilities: [a0] MSI-X: Enable+ Count=32 Masked-
	Capabilities: [100] Advanced Error Reporting
	Capabilities: [138] Power Budgeting <?>
	Kernel driver in use: qla2xxx
	Kernel modules: qla2xxx

# sudo lsscsi
[1:0:0:0]    disk    ATA      WDC  WDS100T1R0A 10WR  /dev/sda 
[2:0:0:0]    tape    IBM      ULTRIUM-TD7      Q386  /dev/st0 
[N:0:2:1]    disk    SAMSUNG MZVLW512HMJP-000H1__1              /dev/nvme0n1

# sudo ltfsck /dev/sg1
LTFS16000I Starting ltfsck, LTFS version 2.5.0.0 (Prelim), log level 2.
LTFS16088I Launched by "ltfsck /dev/sg1".
LTFS16089I This binary is built for Linux (x86_64).
LTFS16090I GCC version is 14.2.0.
LTFS17087I Kernel version: Linux version 6.14.0-15-generic (buildd@lcy02-amd64-022) (x86_64-linux-gnu-gcc-14 (Ubuntu 14.2.0-19ubuntu2) 14.2.0, GNU ld (GNU Binutils for Ubuntu) 2.44) #15-Ubuntu SMP PREEMPT_DYNAMIC Sun Apr  6 15:05:05 UTC 2025 i386.
LTFS17089I Distribution: PRETTY_NAME="Ubuntu 25.04".
LTFS17089I Distribution: DISTRIB_ID=Ubuntu.
LTFS17085I Plugin: Loading "sg" tape backend.
LTFS30209I Opening a device through sg-ibmtape driver (/dev/sg1).
LTFS30250I Opened the SCSI tape device 2.0.0.0 (/dev/sg1).
LTFS30207I Vendor ID is IBM     .
LTFS30208I Product ID is ULTRIUM-TD7     .
LTFS30214I Firmware revision is Q386.
LTFS30215I Drive serial is F002------.
LTFS30285I The reserved buffer size of /dev/sg1 is 262144.
LTFS30205I RSOC (0xa3) returns -20603.
LTFS30263I RSOC returns Power On, Reset, or Bus Device Reset Occurred (-20603) /dev/sg1.
LTFS30262I Forcing drive dump.
LTFS39802W Unknown SCSI OP code 0x1d, use default timeout.
LTFS30205I FORCE_DUMP (0x1d) returns -20601.
LTFS30263I FORCE_DUMP returns Not Ready to Ready Transition, Medium May Have Changed (-20601) /dev/sg1.
LTFS30262I Forcing drive dump.
LTFS39802W Unknown SCSI OP code 0x1d, use default timeout.
LTFS30253I Saving drive dump to /tmp/ltfs_F002------_2025_0608_074723_f.dmp.
LTFS39802W Unknown SCSI OP code 0x3c, use default timeout.
LTFS39802W Unknown SCSI OP code 0x3c, use default timeout.
LTFS30200I Failed to execute SG_IO ioctl, opcode = 3c (22).
LTFS30263I READ_BUFFER returns ioctl error (-21700) /dev/sg1.
LTFS30258W Cannot retrieve drive dump: failed to read buffer (-21700).
LTFS30253I Saving drive dump to /tmp/ltfs_F002------_2025_0608_074723_f.dmp.
LTFS39802W Unknown SCSI OP code 0x3c, use default timeout.
LTFS39802W Unknown SCSI OP code 0x3c, use default timeout.
LTFS30200I Failed to execute SG_IO ioctl, opcode = 3c (22).
LTFS30263I READ_BUFFER returns ioctl error (-21700) /dev/sg1.
LTFS30258W Cannot retrieve drive dump: failed to read buffer (-21700).
LTFS30294I Setting up timeout values from vendor and device.
LTFS17160I Maximum device block size is 1048576.
LTFS11330I Loading cartridge.
LTFS30252I Logical block protection is disabled.
LTFS11332I Load successful.
LTFS17157I Changing the drive setting to write-anywhere mode.
LTFS16014I Checking LTFS file system on '/dev/sg1'.
LTFS30252I Logical block protection is disabled.
LTFS16023I LTFS volume information:.
LTFS16024I Volser (bar code) :       .
LTFS16025I Volume UUID     : 6fa748aa-d50a-4573-a6e1-5064429446e0.
LTFS16026I Format time     : 2025-04-16 21:47:54.794033140 CEST.
LTFS16027I Block size      : 524288.
LTFS16028I Compression     : Enabled.
LTFS16029I Index partition : ID = a, SCSI Partition = 0.
LTFS16030I Data partition  : ID = b, SCSI Partition = 1.

LTFS11005I Mounting the volume from device.
LTFS30252I Logical block protection is disabled.
LTFS11026I Performing a full medium consistency check.
LTFS30200I Failed to execute SG_IO ioctl, opcode = 08 (22).
LTFS30263I READ returns ioctl error (-21700) /dev/sg1.
LTFS12049E Cannot read: backend call failed (-21700).
LTFS17039E XML parser: failed to read a block from the medium (-21700).
LTFS17037E XML parser: failed to read from XML stream.
LTFS17273E XML parser: Detected an I/O error on reading an index from the tape (-21700).
LTFS17016E Cannot parse index direct from medium (-21700).
LTFS11194W Cannot read index: failed to read and parse XML data (-21700).
LTFS30200I Failed to execute SG_IO ioctl, opcode = 08 (22).
LTFS30263I READ returns ioctl error (-21700) /dev/sg1.
LTFS12049E Cannot read: backend call failed (-21700).
LTFS17039E XML parser: failed to read a block from the medium (-21700).
LTFS17037E XML parser: failed to read from XML stream.
LTFS17273E XML parser: Detected an I/O error on reading an index from the tape (-21700).
LTFS17016E Cannot parse index direct from medium (-21700).
LTFS11194W Cannot read index: failed to read and parse XML data (-21700).
LTFS30200I Failed to execute SG_IO ioctl, opcode = 08 (22).
LTFS30263I READ returns ioctl error (-21700) /dev/sg1.
LTFS12049E Cannot read: backend call failed (-21700).
LTFS17039E XML parser: failed to read a block from the medium (-21700).
LTFS17037E XML parser: failed to read from XML stream.
LTFS17273E XML parser: Detected an I/O error on reading an index from the tape (-21700).
LTFS17016E Cannot parse index direct from medium (-21700).
LTFS11194W Cannot read index: failed to read and parse XML data (-21700).
LTFS30200I Failed to execute SG_IO ioctl, opcode = 08 (22).
...
...

Expected behavior
Successful mounting with HBA in a Thunderbolt 3 Expansion enclosure

Additional context
I can almost rule out a problem with Thunderbolt itself, a Windows 11 system with IBM LTFS can at least mount the tape, but accessing it and copying is buggy

[kdev231u98r]

Update: Tried formatting with mkltfs, it works. But mounting still does not work.

sudo mkltfs -d /dev/sg1
LTFS15000I Starting mkltfs, LTFS version 2.5.0.0 (Prelim), log level 2.
LTFS15041I Launched by "mkltfs -d /dev/sg1".
LTFS15042I This binary is built for Linux (x86_64).
LTFS15043I GCC version is 14.2.0.
LTFS17087I Kernel version: Linux version 6.14.0-15-generic (buildd@lcy02-amd64-022) (x86_64-linux-gnu-gcc-14 (Ubuntu 14.2.0-19ubuntu2) 14.2.0, GNU ld (GNU Binutils for Ubuntu) 2.44) #15-Ubuntu SMP PREEMPT_DYNAMIC Sun Apr  6 15:05:05 UTC 2025 i386.
LTFS17089I Distribution: PRETTY_NAME="Ubuntu 25.04".
LTFS17089I Distribution: DISTRIB_ID=Ubuntu.
LTFS15003I Formatting device '/dev/sg1'.
LTFS15004I LTFS volume blocksize: 524288.
LTFS15005I Index partition placement policy: None.

LTFS11337I Update index-dirty flag (1) - NO_BARCODE (0x0x62febf4e7cc0).
LTFS17085I Plugin: Loading "sg" tape backend.
LTFS30209I Opening a device through sg-ibmtape driver (/dev/sg1).
LTFS30250I Opened the SCSI tape device 2.0.0.0 (/dev/sg1).
LTFS30207I Vendor ID is IBM     .
LTFS30208I Product ID is ULTRIUM-TD7     .
LTFS30214I Firmware revision is Q386.
LTFS30215I Drive serial is F002------.
LTFS30285I The reserved buffer size of /dev/sg1 is 262144.
LTFS30294I Setting up timeout values from RSOC.
LTFS17160I Maximum device block size is 1048576.
LTFS11330I Loading cartridge.
LTFS30252I Logical block protection is disabled.
LTFS11332I Load successful.
LTFS17157I Changing the drive setting to write-anywhere mode.
LTFS15049I Checking the medium (mount).
LTFS30252I Logical block protection is disabled.
LTFS15010I Creating data partition b on SCSI partition 1.
LTFS15011I Creating index partition a on SCSI partition 0.
LTFS17165I Resetting the medium's capacity proportion.
LTFS11097I Partitioning the medium.
LTFS30263I MODESELECT returns Mode Parameters Rounded (-20101) /dev/sg1.
LTFS11100I Writing label to partition b.
LTFS11278I Writing index to partition b.
LTFS30205I READ_ATTR (0x8c) returns -20501.
LTFS30263I READ_ATTR returns Invalid Field in CDB (-20501) /dev/sg1.
LTFS30233I Cannot read attribute (-20501).
LTFS11336I The attribute does not exist. Ignore the expected error.
LTFS17235I Writing index of NO_BARCODE to b (Reason: Format, 0 files) 	.
LTFS17236I Wrote index of NO_BARCODE (Gen = 1, Part = b, Pos = 5, F002------).
LTFS11337I Update index-dirty flag (0) - NO_BARCODE (0x0x62febf4e7cc0).
LTFS11100I Writing label to partition a.
LTFS11278I Writing index to partition a.
LTFS30205I READ_ATTR (0x8c) returns -20501.
LTFS30263I READ_ATTR returns Invalid Field in CDB (-20501) /dev/sg1.
LTFS30233I Cannot read attribute (-20501).
LTFS11336I The attribute does not exist. Ignore the expected error.
LTFS17235I Writing index of NO_BARCODE to a (Reason: Format, 0 files) F002------.
LTFS17236I Wrote index of NO_BARCODE (Gen = 1, Part = a, Pos = 5, F002------).
LTFS15013I Volume UUID is: b7d8f4a4-381d-416d-9fb6-af9a3c08b0aa.

LTFS15019I Volume capacity is 5732 GB.
LTFS30252I Logical block protection is disabled.
LTFS15024I Medium formatted successfully.

sudo ltfs -o devname=/dev/sg1 /mnt/ltfs
2584 LTFS14000I LTFS starting, LTFS version 2.5.0.0 (Prelim), log level 2.
2584 LTFS14058I LTFS Format Specification version 2.4.0.
2584 LTFS14104I Launched by "ltfs -o devname=/dev/sg1 /mnt/ltfs".
2584 LTFS14105I This binary is built for Linux (x86_64).
2584 LTFS14106I GCC version is 14.2.0.
2584 LTFS17087I Kernel version: Linux version 6.14.0-15-generic (buildd@lcy02-amd64-022) (x86_64-linux-gnu-gcc-14 (Ubuntu 14.2.0-19ubuntu2) 14.2.0, GNU ld (GNU Binutils for Ubuntu) 2.44) #15-Ubuntu SMP PREEMPT_DYNAMIC Sun Apr  6 15:05:05 UTC 2025 i386.
2584 LTFS17089I Distribution: PRETTY_NAME="Ubuntu 25.04".
2584 LTFS17089I Distribution: DISTRIB_ID=Ubuntu.
2584 LTFS14063I Sync type is "time", Sync time is 300 sec.
2584 LTFS17085I Plugin: Loading "sg" tape backend.
2584 LTFS17085I Plugin: Loading "unified" iosched backend.
2584 LTFS14095I Set the tape device write-anywhere mode to avoid cartridge ejection.
2584 LTFS30209I Opening a device through sg-ibmtape driver (/dev/sg1).
2584 LTFS30250I Opened the SCSI tape device 2.0.0.0 (/dev/sg1).
2584 LTFS30207I Vendor ID is IBM     .
2584 LTFS30208I Product ID is ULTRIUM-TD7     .
2584 LTFS30214I Firmware revision is Q386.
2584 LTFS30215I Drive serial is F002------.
2584 LTFS30285I The reserved buffer size of /dev/sg1 is 262144.
2584 LTFS30294I Setting up timeout values from RSOC.
2584 LTFS17160I Maximum device block size is 1048576.
2584 LTFS11330I Loading cartridge.
2584 LTFS30252I Logical block protection is disabled.
2584 LTFS11332I Load successful.
2584 LTFS17157I Changing the drive setting to write-anywhere mode.
2584 LTFS11005I Mounting the volume from device.
2584 LTFS30252I Logical block protection is disabled.
2584 LTFS30200I Failed to execute SG_IO ioctl, opcode = 08 (22).
2584 LTFS30263I READ returns ioctl error (-21700) /dev/sg1.
2584 LTFS12049E Cannot read: backend call failed (-21700).
2584 LTFS17039E XML parser: failed to read a block from the medium (-21700).
2584 LTFS17037E XML parser: failed to read from XML stream.
2584 LTFS17273E XML parser: Detected an I/O error on reading an index from the tape (-21700).
2584 LTFS17016E Cannot parse index direct from medium (-21700).
2584 LTFS11194W Cannot read index: failed to read and parse XML data (-21700).
2584 LTFS11024E Cannot mount volume: read index failed on the index partition.
2584 LTFS14013E Cannot mount the volume from device.
2584 LTFS30252I Logical block protection is disabled.

[piste-jp]

It looks READ 512KB is failed.

From the log, LTFS failed to reserve a 512KB buffer in the sg driver like below. It just reserve 256KB.

2584 LTFS30285I The reserved buffer size of /dev/sg1 is 262144.

Try sudo mkltfs -d /dev/sg1 -b 262144 and then mount the tape. If it works, your environment cannot handle 512KB read.

[kdev231u98r]

Thank you for your answer.

It works with sudo mkltfs -d /dev/sg1 -b 262144, I can mount the tape. Is LTFS safe to use with 256KB size? Any disadvantages? I can use 256KB for new tapes, I can live with that, but I also want to be able to read existing LTFS tapes with it.

What do you suspect, problems with the driver, HBA or even Thunderbolt? With the same HBA on the mainboard it works without any changes to mkltfs.

[piste-jp]

Is LTFS safe to use with 256KB size?

I don't know what 'safe' means. But using 256KB block keeps tape portability on your environment.

One more thing is your environment cannot mount a tape created somewhere with 512KB block. But a tape created by your environment can be read/write by others.

Any disadvantages?

Disadvantage is read/write performance. It might be degraded slightly (may be 1%-3% under some conditions).

What do you suspect, problems with the driver, HBA or even Thunderbolt?

At this time, I cannot understand what is happening on your system. Because I think you are the first reporter to use thunderbolt expansion enclosure on Linux.

First I would like to know the root cause is thunderbolt expansion enclosure or not. Are you using the same machine between PCIe direct attach and thunderbolt attach ?

[kdev231u98r]

By 'safe' I meant whether problems could occur in the future.

They are different devices, unfortunately I don't have a desktop PC that supports Thunderbolt or could be upgraded.

[piste-jp]

By 'safe' I meant whether problems could occur in the future.

We cannot guarantee anything about problems in the future. If you need this, you need to pay your money to a LTFS product. Take your own risk.

They are different devices, unfortunately I don't have a desktop PC that supports Thunderbolt or could be upgraded.

At this time, I think the most suspicious device is HBA attached to the Thunderbolt box. Try to use a HBA that works with 512KB reserved buffer on another PC.

[kdev231u98r]

Unfortunately no luck with another HBA (HPE / QLogic 16Gb FC Dual-port)

22:00.0 Fibre Channel: QLogic Corp. ISP8324-based 16Gb Fibre Channel to PCI Express Adapter (rev 02)
22:00.1 Fibre Channel: QLogic Corp. ISP8324-based 16Gb Fibre Channel to PCI Express Adapter (rev 02)

13f9 LTFS14000I LTFS starting, LTFS version 2.5.0.0 (Prelim), log level 2.
13f9 LTFS14058I LTFS Format Specification version 2.4.0.
13f9 LTFS14104I Launched by "ltfs -o devname=/dev/sg0 /mnt/ltfs".
13f9 LTFS14105I This binary is built for Linux (x86_64).
13f9 LTFS14106I GCC version is 14.2.0.
13f9 LTFS17087I Kernel version: Linux version 6.14.0-22-generic (buildd@lcy02-amd64-061) (x86_64-linux-gnu-gcc-14 (Ubuntu 14.2.0-19ubuntu2) 14.2.0, GNU ld (GNU Binutils for Ubuntu) 2.44) #22-Ubuntu SMP PREEMPT_DYNAMIC Wed May 21 15:01:51 UTC 2025 i386.
13f9 LTFS17089I Distribution: DISTRIB_ID=Ubuntu.
13f9 LTFS17089I Distribution: PRETTY_NAME="Ubuntu 25.04".
13f9 LTFS14063I Sync type is "time", Sync time is 300 sec.
13f9 LTFS17085I Plugin: Loading "sg" tape backend.
13f9 LTFS17085I Plugin: Loading "unified" iosched backend.
13f9 LTFS14095I Set the tape device write-anywhere mode to avoid cartridge ejection.
13f9 LTFS30209I Opening a device through sg-ibmtape driver (/dev/sg0).
13f9 LTFS30250I Opened the SCSI tape device 1.0.0.0 (/dev/sg0).
13f9 LTFS30207I Vendor ID is IBM     .
13f9 LTFS30208I Product ID is ULTRIUM-TD7     .
13f9 LTFS30214I Firmware revision is Q386.
13f9 LTFS30215I Drive serial is F002------.
13f9 LTFS30285I The reserved buffer size of /dev/sg0 is 262144.
13f9 LTFS30205I RSOC (0xa3) returns -20603.
13f9 LTFS30263I RSOC returns Power On, Reset, or Bus Device Reset Occurred (-20603) /dev/sg0.
13f9 LTFS30262I Forcing drive dump.
13f9 LTFS39802W Unknown SCSI OP code 0x1d, use default timeout.
13f9 LTFS30253I Saving drive dump to /tmp/ltfs_F002------_2025_0630_105958_f.dmp.
13f9 LTFS39802W Unknown SCSI OP code 0x3c, use default timeout.
13f9 LTFS39802W Unknown SCSI OP code 0x3c, use default timeout.
13f9 LTFS30200I Failed to execute SG_IO ioctl, opcode = 3c (22).
13f9 LTFS30263I READ_BUFFER returns ioctl error (-21700) /dev/sg0.
13f9 LTFS30258W Cannot retrieve drive dump: failed to read buffer (-21700).
13f9 LTFS30294I Setting up timeout values from vendor and device.
13f9 LTFS30205I TEST_UNIT_READY (0x00) returns -20209.
13f9 LTFS17160I Maximum device block size is 1048576.
13f9 LTFS11330I Loading cartridge.
13f9 LTFS30205I LOAD_UNLOAD (0x1b) returns -20209.
13f9 LTFS30263I LOAD_UNLOAD returns Medium Not Present (-20209) /dev/sg0.
13f9 LTFS30262I Forcing drive dump.
13f9 LTFS30253I Saving drive dump to /tmp/ltfs_F002------_2025_0630_110008_f.dmp.
13f9 LTFS30200I Failed to execute SG_IO ioctl, opcode = 3c (22).
13f9 LTFS30263I READ_BUFFER returns ioctl error (-21700) /dev/sg0.
13f9 LTFS30258W Cannot retrieve drive dump: failed to read buffer (-21700).
13f9 LTFS30205I READPOS (0x34) returns -20203.
13f9 LTFS30263I READPOS returns Initializing Command Required (-20203) /dev/sg0.
13f9 LTFS30262I Forcing drive dump.
13f9 LTFS30253I Saving drive dump to /tmp/ltfs_F002------_2025_0630_110019_f.dmp.
13f9 LTFS30200I Failed to execute SG_IO ioctl, opcode = 3c (22).
13f9 LTFS30263I READ_BUFFER returns ioctl error (-21700) /dev/sg0.
13f9 LTFS30258W Cannot retrieve drive dump: failed to read buffer (-21700).
13f9 LTFS12016E No medium present.
13f9 LTFS11331E Failed to load the cartridge (ltfs_load_tape).
13f9 LTFS17189I Device is becoming ready (-20203).
13f9 LTFS30252I Logical block protection is disabled.
13f9 LTFS17157I Changing the drive setting to write-anywhere mode.
13f9 LTFS11005I Mounting the volume from device.
13f9 LTFS30252I Logical block protection is disabled.
13f9 LTFS30200I Failed to execute SG_IO ioctl, opcode = 08 (22).
13f9 LTFS30263I READ returns ioctl error (-21700) /dev/sg0.
13f9 LTFS12049E Cannot read: backend call failed (-21700).
13f9 LTFS17039E XML parser: failed to read a block from the medium (-21700).
13f9 LTFS17037E XML parser: failed to read from XML stream.
13f9 LTFS17273E XML parser: Detected an I/O error on reading an index from the tape (-21700).
13f9 LTFS17016E Cannot parse index direct from medium (-21700).
13f9 LTFS11194W Cannot read index: failed to read and parse XML data (-21700).
13f9 LTFS11024E Cannot mount volume: read index failed on the index partition.
13f9 LTFS14013E Cannot mount the volume from device.
13f9 LTFS30252I Logical block protection is disabled.

Both HBAs work with direct connection to the mainboard via PCIe.

Is there anything else I could try to make it work via Thunderbolt?

[piste-jp]

The reserved buffer is still 256KB.

13f9 LTFS30285I The reserved buffer size of /dev/sg0 is 262144.

May be thunderbolt box have a kind of limitation about transfer length.