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Best Effort Lock (button push eject method)
(KB # 580FE1DE)

Best Effort Lock (button push eject method)

Tandberg Data has a host software work around for Microsoft Windows users known as “Best Effort Lock” that allows button-push eject to work in most cases. Tandberg Data does NOT consider this the ideal solution and should be used at your own risk. We are still trying to understand the root cause for eject failures on some systems. Most eject failures are caused by open handles to the device that keep the eject software from getting an exclusive volume lock to allow for the safest eject possible. You may need to obtain the latest version of RDX Utility from our downloads section before this workaround is available (you need RDX Utility release 1.31 or later).

Most eject failures are caused by open handles to the device that keep the eject software from getting an exclusive volume lock to allow for the safest eject possible.For more background on this issue and troubleshooting ideas please see Microsoft eject Volume Lock fails with "Access Denied"

Workaround: (button-push eject only)

Open Windows Explorer

Navigate to the “C:\Program Files\RDX\Service” (32bit system) or “C:\Program Files(x86)\RDX\Service\” (64bit system) directory
Double click to execute “EnableBestEffort.bat”

Workaround Details:
This batch file sets a registry key value that is used by the RDXmon service to bypass the requirement for exclusive volume lock (FSCTL_LOCK_VOLUME IOCTL recommended by Microsoft KB article 165721.) The Best Effort Lock procedure monitors the RDX device for write operations; if it determines that no writes are in progress (resolution is < 1MB in 3 seconds) the Best Effort Lock procedure skips the exclusive lock through FSCTL_LOCK_VOLUME_IOCTL and continues the eject operation with an OS call to dismount the volume. This will terminate any open handles and could potentially cause problems with some applications. Use this eject method only if you have tried the other suggested eject fixes and you are still having eject problems.

Cautions:
Best Effort Lock monitors for active write operations. However, if the write operation in progress is very slow and/or very small (< 1/MB in 3 seconds) then it is possible to eject the cartridge part way through a write operation. We haven’t seen a problem with small files ( < 1MB ) because the OS call to dismount flushes the data. In the case where a very slow accumulation of data is taking place to a large file; that file will be incomplete. The file is corrupt since doing a binary compare to the source file would yield errors. However, the file is still accessible and the volume is still accessible on re-insertion.

Tandberg Data has never seen any degradation of the file system on the RDX cartridge as a result of using this workaround and believes catastrophic file system degradation is very unlikely to occur, however this cannot be guaranteed and you should use this workaround at your own risk. For additional troubleshooting steps please consider contacting Tandberg Data support instead.

Positives:
In most cases this workaround will allow button eject to work as expected with Windows operating systems by ignoring applications or system processes that keep an open file handle on the RDX device preventing exclusive lock and the eject process from completing.

Tandberg Data has also seen an unexpected benefit on some systems from using the Best Effort Lock workaround. Open handles to the RDX are closed when the volume is dismounted and the open handles associated with the eject problem tend to stay closed until the next system reboot. You may notice that normal scheduled ejects from you backup application work after doing a single push-button eject with Best Effort Lock enabled.

Restoring Default Behavior:
The registry key value controlling Best Effort Lock can be set back to its default state by executing “DisableBestEffort.bat”. This restores the default behavior requiring a volume lock as part of the eject sequence as recommended by KB article 165721.



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