st_san_safe parameter in the kernel

[Dan Copeland]

Hi guys,

I am missing st_san_safe paramater in the kernel for a couple of my 11.11 servers. I have it in all my other 11.11 servers. I thought this comes with the OS, but I might be mistaken. Is there a patch which puts this in the kernel. Please advise.

Thanks

[Steven E. Protter]

This patch corrects a spelling problem in a prior patch.

http://www1.itrc.hp.com/service/cki/patchDocDisplay.do?patchId=PHKL_29248

You may have a patch installed that causes a misspell of this parameter. Strange.

Check the doc and kmtune | grep mis_spelled parm and see if you are a victim.

or

swlist -l product | grep -i PHKL_#####

SEP

[Helen French]

This parameter has been added with the 'stape' driver cumulative patch on HP-UX:

PHKL_26785 (for HP-UX 11.11) and
PHKL_26784 (for HP-UX 11.00)

This parameter will be useful during backup troubleshooting, also affects mksf, lssf etc.

[Mark Grant]

Also, I am pretty sure that this parameter forces you to use the no rewind device on your tape devices so remember to update your backup software.

[Lee Huei]

From the latest stape patch PHKL_28217, a new tunable called st_san_safe was added with a default state of disabled.

When enabled (ST_SAN_SAFE = 1) , the tunable forces the stape driverto fail all opens to device files without the no-rewind-on-close option with the errno EINVAL. The stape driver will also log an entry into the syslog like the following:


vmunix: SCSI TAPE: dev = 0xcd002000 Failed open -st_san_safe enabled

When st_san_safe is enabled, mksf will not create new device files without the no-rewind-on-close option. The mksf command will fail with an error indicating an invalid option was provide in the command line arguments. With st_san_safe enabled, lssf will not fully decode the density attribute of a special device file.

With this ST_SAN_SAFE enabled, all HPUX backup commands such as tar, fbackup and make_recovery will require you to use the 'no rewind' tape device files.

The 'no rewind' tape device files contain the 'n' option in the device file. The 'no rewind' device files should look like

/dev/rmt/*mn

where "*" is some number.

However fbackup does not support the usage of "no rewind on close" device files (the man page explicitely says to use a "rewind on close" device). This is mainly because the tool can not handle multiple archives on a single tape.

[Dan Copeland]

These patches PHKL_28217 and PHKL_26785 (for HP-UX 11.11) are not installed on the other 11.11 servers which has these parameter in the kernel. The server under consideration which is also a 11.11 seems to be missing the st_san_safe parameter. Any thoughts?

[Bernhard Mueller]

Frank,

you just need to double check the information for PHKL_26785 guess the warning there explains it. There are superseding patches PHKL_28217 (**) and PHKL_29248 (*).

Regards,
Bernhard