Tar command issue with Ultrium LTO-4 1760 on SAS bus

[JACC]

Error received in dmesg ( kernel ring buffer ) when running:
tar -cvb 256 -f /dev/st0 ./filename

st0: Block limits 1 - 16777215 bytes.
st0: Failed to read 126976 byte block with 8192 byte transfer.

The odd behavior is the tar command performs without issue as long as the blocking factor is 248 or less. Anything above fails. I can also recreate the issue using the "dd" command (see following).

dd if=/dev/zero of=/dev/st0 bs=126976 count=2 (248 x 512 Bytes - equivalent to tar command using -b 248)
2+0 records in
2+0 records out
253952 bytes (254 kB) copied, 10.3574 seconds, 24.5 kB/s


dd if=/dev/zero of=/dev/st0 bs=131072 count=2 (256 x 512 Bytes - equivalent to tar command using -b 256)
dd: writing `/dev/st0': Device or resource busy
1+0 records in
0+0 records out
0 bytes (0 B) copied, 16.0792 seconds, 0.0 kB/s




Output from mt status command:

drive type = Generic SCSI-2 tape
drive status = 1174405120
sense key error = 0
residue count = 0
file number = 0
block number = 0
Tape block size 0 bytes. Density code 0x46 (unknown).
Soft error count since last status=0
General status bits on (41010000):
BOT ONLINE IM_REP_EN



System Info:

HP Proliant DL380R06 Rack Mount

52: SCSI 200.0: 10601 Tape
[Created at scsi.1363]
UDI: /org/freedesktop/Hal/devices/pci_103c_323a_scsi_device_lun0_scsi_generic
Unique ID: Er1e.jH5QXkQpQf6
Parent ID: cuhJ.XEXEELn_ra7
SysFS ID: /class/scsi_tape/st0
SysFS BusID: 2:0:0:0
SysFS Device Link: /devices/pci0000:00/0000:00:08.0/0000:0a:00.0/host2/target2:0:0/2:0:0:0
Hardware Class: unknown
Model: "HP Ultrium 4-SCSI"
Vendor: "HP"
Device: "Ultrium 4-SCSI"
Revision: "U52D"
Driver: "cciss", "st"
Device File: /dev/st0 (/dev/sg1)
Device Files: /dev/st0, /dev/tape/by-id/scsi-3500110a0012cef1a-st, /dev/tape/by-path/pci-0000:0a:00.0-scsi-0:0:0:0-st
Device Number: char 9:0 (char 21:1)
Config Status: cfg=new, avail=yes, need=no, active=unknown
Attached to: #48 (RAID bus controller)


output from modinfo cciss:

filename: /lib/modules/2.6.16.60-0.58.1-smp/kernel/drivers/block/cciss.ko
license: GPL
description: Driver for HP Smart Array Controllers version 3.6.24-4
author: Hewlett-Packard Company
depends: scsi_mod
vermagic: 2.6.16.60-0.58.1-smp SMP gcc-4.1
parm: cciss_tape_cmds:number of commands to allocate for tape devices
(default: 6) (int)
parm: cciss_allow_hpsa:Prevent cciss driver from accessing hardware kn
own to be supported by the hpsa driver (int)




output from modinfo st:

filename: /lib/modules/2.6.16.60-0.58.1-smp/kernel/drivers/scsi/st.ko
alias: char-major-9-*
license: GPL
description: SCSI tape (st) driver
author: Kai Makisara
srcversion: 823F47591D48D44F0CEBA94
depends: scsi_mod
supported: yes
vermagic: 2.6.16.60-0.58.1-smp SMP gcc-4.1
parm: buffer_kbs:Default driver buffer size for fixed block mode (KB;
32) (int)
parm: max_sg_segs:Maximum number of scatter/gather segments to use (25
6) (int)
parm: try_direct_io:Try direct I/O between user buffer and tape drive
(1) (int)
parm: try_rdio:Try direct read i/o when possible (int)
parm: try_wdio:Try direct write i/o when possible (int)

I will be happy to supply any other additional information which may be helpful in resolving this issue. Please be patient with me, manipulating a system at this level is very knew to me.

I should also add LTT was run on the system and no issues were found.


Thanks in Advance

JACC

[Steven Schweda]

I know nothing, but it sounds like a (buffer
size?) limitation in the tape driver or in
the drive itself.

Does "man st" tell you anything? Drive
documentation?

I don't do much with tape on any GNU/Linux
system, but is a block size that big normal?


> [...] Anything above fails. [...]

"Doctor, it hurts when I do this."

"Don't do that."

[JACC]

Thanks for the prompt reply Steven.

LOL over the "don't do that".

There are a couple of things which are driving me crazy about this issue. We have 300 LTO3's in the field, 74 LTO-4 and a sprinkling of about 250 others. Granted the majority of servers running SUSE but on "Different hardware". In all cases the blocking factor for tar has been 500. So now my choice is to migrate 600 servers to a lower blocking factor which also then becomes a historical recovery issue as well or figure out why this is not working.

I have a very similar system running the HP Proliant server on SUSE with an LTO-4 on a scsi bus (NON SAS) and it works just fine.

So why all of the sudden a difference?

I agree there must be some sort of lower level setting whether it be a kernel param or driver issue I can't quite figure out. And as I said before hardware really isn't my area (i.e lack experience in lower level configuration).


Thanks

JACC

[Jimmy Vance · Accepted solution]

I sent your question to the group who works on the cciss driver, I'll let you know what they say.

[JACC]

Thanks very much Jimmy, greatly appreciated.

JACC

[Jimmy Vance]

Are you using the embedded Smart Array 410i? Is it zero memory or does it have a cache module?

[JACC]

HP DL380G6 CTO Chassis
(2) Intel Xeon Processor X5560 2.80 GHz CPU's
32GB PC3-10600R-9 2Rx4 DDR3 Memory
(2) HP 460W CS HE Gold Power Supply's
HP Smart Array P410/512MB with BBWC
HP Slim SATA DVD-RW Optical Drive
(2) HP 146GB 3G SAS 15K SFF DP ENT HDD
Hewlett-Packard ILO ADV 1-SVR INCL 1YR TS&U SW
HP SC44Ge Host Bus Adapter
3YR 4HR24X7 HW PROLIANT DL380 CAREPACK
HP StorageWorks 1U SAS Rack-Mount Kit with one LTO-4 Ultrium 1760
3YR UPG WARR ONSITE 24X7 4HR 1U TAPE ARRAY
HP StorageWorks MSA60 Storage Shelf (12 SAS or SATA LFF)
(12) HP 300GB 6G SAS 15K 3.5" DP ENT HDD
HP Smart Array P800/512 BBWC Controller
2M EXT MINI-SAS X4 SFF-8088 TO MINI-SAS X4 SFF-80

[Jimmy Vance]

Thanks for the system detail. Which controller do you have the tape drive connected to?

HP Smart Array P410/512MB with BBWC
HP Smart Array P800/512 BBWC Controller
HP SC44Ge Host Bus Adapter

[JACC]

Sorry Jimmy ! I really appreciate your help.

Do you know the command to display the info?

[Jimmy Vance]

I think the easiest way is to just look and see what controller the cable from the tape drive connected to.

The reason I ask is with the specs of the systems, just a casual observation one would think the following

The embedded
HP Smart Array P410/512MB with BBWC
is probably conencted to the
(2) HP 146GB 3G SAS 15K SFF DP ENT HDD
in the server drive bays

And the
HP StorageWorks MSA60 Storage Shelf (12 SAS or SATA LFF) with
(12) HP 300GB 6G SAS 15K 3.5" DP ENT HDD
is conencted to the
HP Smart Array P800/512 BBWC Controller

Which leaves the
HP SC44Ge Host Bus Adapter
Which would be the logical choice for the controller connected to the tape drive

Your original posts shows the tape is using the cciss driver which is for the P410 and P800 controllers. The SC44Ge use the mptlinux drivers.