Known issues, Device access issues (rsm on windows) – HP StoreEver TapeAssure Software User Manual
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Known issues
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Device access issues (RSM on Windows)
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Poor performance on Windows 2003 Server systems with EBS installations
Device access issues (RSM on Windows)
On many operating systems, most backup applications require exclusive access to tape devices
to avoid interference between multiple processes accessing the same device. While there are
differences between operating systems regarding how services and applications run, how they
are monitored, and which error messages are displayed by L&TT when a conflict is detected, the
basic issue remains the same: devices may show as inaccessible in L&TT if they are still claimed
by another process.
As a result, you cannot run L&TT and a backup application at the same time. If a backup application
is still running, L&TT is unable to gain access to the tape drives, and functionality in L&TT is restricted.
Similarly, if L&TT is running and a backup application tries to execute a scheduled job, the job
may fail because it cannot access the drive. It should be noted that backup applications refers to
service processes, drivers, or typical backup software applications. The Windows Removable
Storage Management service (RSM) is an example of a process that blocks access to tape libraries
and drives; it must be disabled or shut down before using L&TT. The L&TT Startup screen contains
a reminder of this. For more information on RSM, including how to disable and re-enable it, see
On large SANs, it is often impossible to entirely close all software applications while trying to run
L&TT on a single drive. In these situations, use the SAN awareness features to bypass conflicts on
all other devices, and focus on a single robotics controller or tape drive. However, even in this
scenario, this single device must be released from control of any other software via appropriate
means.
On the Windows platform, there are two I/O modes available: NT Miniport I/O mode and ASPI
I/O mode. The ASPI I/O mode has the ability to circumvent these exclusivity restrictions because
it does not honor the security system built into the server variants of Windows, related to mutual
exclusivity. This is also the reason that Microsoft views ASPI as a deprecated I/O model that should
only be used when necessary. If you use ASPI to circumvent the exclusive access restriction, take
extreme care to understand any interference that may occur, and interpret results accordingly.
Poor performance on Windows 2003 Server systems with EBS installations
Many of the ISV Backup Applications supported by HP request or require that the RSM service be
disabled. When the Windows 2003 server is rebooted, even though RSM is disabled, it continues
to initiate the Test Unit Ready (TUR) SCSI command indefinitely on all connected removable devices.
This can cause issues with performance in an environment with many shared tape devices. See
the Microsoft Knowledge Base Article 842411 at
for instructions on how to work around this problem.
Additional interactive device troubleshooting content
HP Guided Troubleshooting, also known as FireFly, is an interactive, web-based, guided
troubleshooting and reporting utility for an increasing number of HP product including HP tape
devices. Use FireFly whenever possible to troubleshoot problems with tape based devices. It contains
logically-oriented issue paths to guide you through the troubleshooting exercise in an orderly fashion
by listing the most probable causes first in the issue path flow.
To begin using FireFly, browse to
select your product type and
answer the questions on each screen. Initially the questions will narrow your product type and
configuration, and then they will focus on the issue symptom and, hopefully, lead to root cause
and a suggested action to resolve the issue. In some cases there will be suggested links to other
support documents as well as recommendations on when and how to L&TT.
108 Troubleshooting