[Bacula-users] ULTRIUM-HH6 Block Size Limits with Adaptec 78165 or Other Issue?

[Drew V. S. <dr...@nu...>]

Greetings,

I have run into an issue and am looking for input. I have a SAS tape 
autoloader with an IBM HH-LTO6 drive running the newest firmware.
It is currently connected to a Adaptec 78165 HBA/Raid controller via SAS.

The issue I am having is when I attempt to modify the block-size to 
anything over 256KB that BareOS writes to tape, it fails. To simplify 
troubleshooting I have opted to use a combination of btape and dd to 
test block-size adjustments.


Each test I perform I rewind the tape, write EOF and rewind again. I'm 
not missing a step here, right? Should I be able to write to a tape in 
this way with a different block size if I've used it at a different 
(smaller) size before?

I am querying the tape-drive in the autoloader directly, the autoloader 
should not be part of the problem.

Writing at anything under and at 256Kb works fine but is slow.

The output from tapeinfo is:

tapeinfo -f /dev/nst0
Product Type: Tape Drive
Vendor ID: 'IBM     '
Product ID: 'ULTRIUM-HH6     '
Revision: 'G9P1'
Attached Changer API: No
SerialNumber: '10WT077984'
MinBlock: 1
MaxBlock: 8388608
SCSI ID: 0
SCSI LUN: 0
Ready: yes
BufferedMode: yes
Medium Type: 0x68
Density Code: 0x5a
BlockSize: 0
DataCompEnabled: no
DataCompCapable: yes
DataDeCompEnabled: yes
CompType: 0xff
DeCompType: 0xff
Block Position: 5
Partition 0 Remaining Kbytes: -1
Partition 0 Size in Kbytes: -1
ActivePartition: 0
EarlyWarningSize: 0
NumPartitions: 0
MaxPartitions: 3

As you can see the block size limit for the drive itself is ~8MB...

Here is an output from mt:

mt -f /dev/nst0 status
SCSI 2 tape drive:
File number=0, block number=0, partition=0.
Tape block size 0 bytes. Density code 0x5a (no translation).
Soft error count since last status=0
General status bits on (41010000):
  BOT ONLINE IM_REP_EN

Here is an attempt to write at a 256K block:

dd if=/dev/zero of=/dev/nst0 bs=256k count=1
1+0 records in
1+0 records out
262144 bytes (262 kB) copied, 1.9402 s, 135 kB/s

Here is the failure at 512K:

dd if=/dev/zero of=/dev/nst0 bs=512k count=1
dd: error writing ‘/dev/nst0’: Device or resource busy
1+0 records in
0+0 records out
0 bytes (0 B) copied, 1.56954 s, 0.0 kB/s


It will fail with anything over 256K, even 257K.

There are no errors in my system logs.

I suspect either I have a configuration error here or am missing 
something simple OR the Adaptec 78165 raid controller is limiting the 
block size before I write to tape. Adaptec support is unable to confirm 
this. Is there a way I can prove this or does anyone have any guidance 
on how to continue troubleshooting this issue?

Thanks!

--drewv