HP Tape Library Interface Manager Software - Manual (Page 87)

Chapter 4 SAN Environments 87
Ch
apter 4
1. Set the static kernel tunable parameter st_ats_enabled to OFF (0).
This can be done from the Kernel Configuration window of HP-UX system
administration tool (SAM) shown in Figure 25 and requires a kernel
rebuild and system reboot. When this parameter is enabled an implicit
SCSI reserve and release is performed during the open and close
sequence in the tape driver. This default was originally designed for ATS
services with MC/ServiceGuard. For SAN configurations, this parameter
needs to be disabled for the reasons described earlier.
Figure 25 Configurable Parameters Screen
Note When MC/ServiceGuard is enabled for ATS, the ATS services
provide a mechanism for automatically cleaning up reservations
from a second host.
2. Configure the Tape Device Monitor (dm_stape) of the Event Monitoring
System (EMS) to not run on the host participating in the tape SAN.
The EMS service periodically polls the tape devices to monitor their health.
When this occurs while another server is accessing the tape device,
backup operations may be disrupted, time out and abort.