“Tape Persistence” means that the tape drives for a tape library use symbolic names. These names stay unique during server reboots, no matter in which order the operating system discovers the tape drives. Without the feature during reboots it could be possible that the SCSI addresses are changed.
Normally the default behaviour of Windows is not a problem for Data Protector since the mechanism “Automatically detect changed SCSI addresses” will discover the new SCSI addresses using the serial number of the tape drive. However, in environments with several tape libraries attached to a server (i.e. when virtual tape libraries are used) the default Windows behaviour might mix the SCSI addresses between different library tape drives. The integrated mechanism in Data Protector will require in these cases some time to correct the problem with the changed SCSI addresses and will display some errors during the jobs. Using tape persistence the behaviour of Windows will be changed and in example a tape drive named “Tape0” becomes a symbolic name “Tape1236572535” (the symbolic name cannot be configured). With these new names error messages in Data Protector are prevented and the SCSI addresses or tape names stay unique.
To enable tape persistence for Windows copy the code below, insert into text editor and save the content as .reg file. Execute the reg file and reboot the System. In addition RSM is disabled. Don’t forget to install the HP tape drivers, the installation routine can be downloaded within the corresponding HP Library.
Update: To use persistence fot the library robotic the additional key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MChgr\Persistence=00000001 is required. In this example the device Changer1:0:0:0 becomes the symbolic name Changer2147483646:0:0:0. With this feature enabled the robotic stays unique as it is the case with tape drives during reboots.
Windows Registry Editor Version 5.00 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\hplto] "AutoRun"=dword:00000000 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Tape] "Persistence"=dword:00000001 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MChgr] "Persistence"=dword:00000001 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NtmsSvc] "Start"=dword:00000004
Das ist ja alles ganz schön, funktioniert nur leider nicht für Changer. 🙂 Ich nutze das mittlerweile nicht mehr und verwende nur das Detect changed SCSI address flag auf den Geräten.
Grüße,
Sebastian
Hallo Sebastian, doch… ich hatte noch vergessen das für den Changer zu dokumentieren, der Artikel ist jetzt aktualisiert.
Grüße
Daniel
This is a great article and something that we have been battling with for a few years. I have one quick question, if I enable this setting and reboot would I have to re-scan all Robots and Drives on each media agent server from within the Data Protector interface or should it just work?
Thanks again.
Spencer
Hi Spencer,
you would need to rescan the drives and robotic and change the SCSI addresses after the reboot… But the good news, this will be the last time…
Best regards
Daniel
Perfect! Thanks for the info.
Hi Daniel
This path not found. Create the folder and the value? What is it for? Thank you
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NtmsSvc]
“Start”=dword:00000004
also, do you install on MA or CM or both? is HP tape drivers required for VTL? thanks
i mean also, do you run the reg values on MA or CM or both
MA only.
Hi,
Enable it on clients with installed MA, HP tape drivers are required.
Best regards
Daniel
Hi, this required on W2K3 only on all clients with installed MA. NtmsS stands for Removable Storage Service.
Best regards
Daniel
great post, thanks admin i learned so much from this post.
Hallo Daniel,
ich bin schon seit mehreren Tagen dabei Persistent Binding unter DP 7 einzurichten, komme aber bei den Laufwerken nicht weiter.
Ich hatte zuerst im Forum angefragt und dort wurde gesagt, dass man am FC HBA Persisten Binding für alle Tapes und Drives aktivieren muss. Das habe ich mittels SANSurfer durchgeführt, bei deinem Post ist hiervon aber nicht die Rede, ist das nun überflüssig, oder nicht?
Des Weiteren habe ich zwar meine Roboter (Changer/Libraries) schon umstellen können, jedoch schaffe ich es nicht auch die Bandlaufwerke permanent an eine Adresse zu binden. Hast du evtl. noch einen Tip?
Weder die physischen (IBM LTO5 (Overland NEO2000e)) noch die virtuellen (HP LTO5 (HP HP (StorageWorks D2D4324 – G02)) Laufwerke zeigen mir eine permantene Adresse an.
Besten Dank!
Gruß
Tobias
Hi Tobias,
Hast Du W2012 am Start?
Mein Artikel funktioniert momentan nur bis Windows 2008.
Grüße
Daniel
Hallo Daniel,
danke fürs Feedback.
Nein auf dem Backupserver läuft W2K8 R2.
Gruß
Tobias
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