Turning off cmtaped messages in syslog.log

[Stephen Doud]

Hello fellow ServiceGuard enthusiasts,

The Response Center has received a number of cases where cluster administrators are concerned about the message:
cmtaped[2050]: cmtaped: There are no ATS devices on this cluster.

That said, many users of ServiceGuard do not know that cmtaped is used by the ATS subsystem, and are alarmed when seeing the above messages. The ATS (advanced tape services) feature was added to the ServiceGuard product in February 1999. It allowed up to 4 nodes to negotiate direct access to a tape library. One requirement was that the nodes share the tape library using a
Fibre Channel SCSI mux. Due to this additional hardware requirement and other more popular backup strategies, ATS has been a fairly unused feature.

For this reason, I have written document UMCSGKBRC00010526
TITLE: Disabling ATS (Advanced Tape Services) and logging

The core of the document resolution is this:

Temporary resolution:
To disable the ATS features and logging while the node is still in the cluster, perform these commands:

# echo 'st_ats_enabled?W 0' | adb /stand/vmunix
and
# echo 'st_ats_enabled/W 0' | adb /stand/vmunix /dev/mem

Permanent resolution:
To permanently disable Advanced Tape Services and associated logging, turn off the st_ats_enabled parameter in the kernel using SAM (set it to zero), regen the kernel, and reboot on the new
kernel.

One note: current versions of ServiceGuard come with this parameter set to 0, so the messages should not appear in new clusters.
Upgraded clusters on the other hand may require the fore-mentioned configuration change to eliminate the unnecessary logging.

-s.

[Carsten Krege]

As a side note:

The MC/ServiceGuard Division has determined that the MC/ServiceGuard
Advanced Tape Services (ATS) feature will no longer be enhanced, and will be
removed from all future versions of MC/ServiceGuard and ServiceGuard OPS
Edition (= SGeRAC) that run on HP-UX versions other than 11.0 and 11.11 (e.g. SG A.11.14.01 for HPUX 11.22 doesn't include ATS anymore). This is partly due to the fact that the only supported Fibre Channel SCSI Bridge, the 4/2,
is required for ATS, and is no longer available. Additionally, tape backup
software available now offers similar functionality to ATS, and allows more
flexibility for supported configurations.

Carsten