Virtual TapeServer 6.04.03.02 for NonStop Servers Release Notes

Resolved Issues and Enhancements | 6
Resolved Issues and Enhancements
The following changes have been incorporated into the software since the 6.04.03 release.
Hardware and configuration
 HBAs used a default SCSI ID of 7. In most cases, SCSI ID 7 may conflict with the SCSI
ID used by host systems, which is also 7. Now, VTS uses default ID 6. (TL-4117)
 Exports to SCSI physical drives may have failed. When simultaneously running
backups to a VTD and writing to external SCSI storage device, various errors could occur
that caused the loss of use of the SCSI storage device. Exports may have failed with an
RC9 return code. This was due to a problem with the VTS version of the Adaptec AIC
driver used for writing to SCSI targets. Now, you can disable the VTS target mode driver
on the Manage Systems Limits page. Doing so will use the native Linux SCSI driver,
which will perform much faster. This option is only available if you do not have SCSI
VTDs.(TL-3924, EAR 5702, EAR 5744)
General operations
 Tape write buffering is now enabled. Tape write buffering has been added to improve
performance. This feature is enabled by default. 134MB of allocated shared memory is
provided to support a queue depth of 4 (256K writes). (TL-4127)
Four parameters can be added to vts.conf to change the default behavior:
engine_MultiStreamYield - Defines the number of events that can occur before VTS forces
a sched_yield(). Values: 1 to 20,000. 0 disables this feature.
engine_TapeWriteCmdDepth - Defines the number of write commands that will be
responded to (buffered) without writing the data to disk. Values: 1 to 3.
engine_TapeWriteStateTimeout - Sets the timeout value in milliseconds that is compared
to the time between commands. If a new WRITE command comes in while VTS is idle and
the previous command occurred longer ago than this value, the state is reset to IDLE so
that the unit attention can be picked up (write buffering does not occur). Values: greater
than 0. 32-bit signed integer.
engine_DisableTapeWriteBuffering - Disables tape write buffering. Values: YES and NO.
Defaults:
engine_MultiStreamYield =2000 events
engine_TapeWriteCmdDepth=3 cmds
engine_TapeWriteStateTimeout=200mS
engine_DisableTapeWriteBuffering="NO"
 Inconsistent information was sent to host about media type. When a host
requested information, including the media type in use, from VTS, different responses
were issued depending on whether the tape was loaded. Also, the type given may not have
been one that was applicable for that tape type. This has been fixed. (TL-4152, EAR 6222)
 Serial number could be autogenerated to include a single digit. Serial numbers
could be autogenerated as single digits, which may not have been acceptable to host
systems. The autogenerated serial numbers were based on the BTLI of the drive. Now, the
serial number includes at least six digits; the last digits are the BTLI. (TL-3946)