HPE 3PAR StoreServ Storage

3PAR VLUN Discrepancy


3PAR VLUN Discrepancy



I have a strange issue on my 3PAR 7200 when trying to present out some VV's in a VVS to a Host Set. 


First of all, a little history...


I have previously created 16 VV's of 3000GiB in size as part of a VVS called WFM_CACHE, this VVS was then presented out to a host called PROD_T4 as part of a data migration exercise. - Unfortunately it was at this point it was noted that the LUN sizings I had used were not in alignment with the Solaris HA solution we were to then attach the LUN's to and so the VVS was unexported from host PROD_T4 and the VLUN's, VVS and VV's removed from the 3PAR. 


A new set of LUN's were then created of the correct sizings and now require presenting to the solaris HA Cluster for configuration before then being unpresented and presented to the PROD_T4 host to start the DM again. 


It was at this point I noticed something odd...


Although I've created a different number of LUN's than before and of different sizes to meet the overall capacity requirements, I kept the VVS set name I had used previously when I recreated the VV's and VVS. 


So, NEW VV's, NEW VVS, (albiet with the same name as before) and soon to be NEW VLUNs when I export to the Host Set 'T4_DB_HA' which contains hosts 'T4_DB1' and 'T4_DB2'.


So, I go through the export wizard and select VVS 'WFM_CACHE' to be exported, I then choose Host Set 'T4_DB_HA'.


Behold! VLUN ID's available for use? 17-256!!


Where are VLUN ID's 1-16?!


I was sure to clean up all VLUN's when I unexported and removed the previous VLUN's/VVS and VV's, yet I'm presenting out to a different host set then before, the only thing in common is the VVS name. 


I am wondering therefore if there is something that can be cleaned up at 3PARCLI level relating to the VVS which of course upon creation of the new VVS (with the same name as before) may have tied two DB tables back together somewhere in the underyling meta data and caused it to believe VLUN ID's 1-16 are still in use somehow?


In terms of production, this is not an issue for us, as we can be certain we will never exceed 256 VLUN's on this host during the life of the system.


But it does pose an interesting question about how the system manages the removal of VLUN's etc and what happens if you recreate VVS's with names used previously, which in my scenario above can often be the case if errors are made in pre-production and things are scrubbed and started again....


Any ideas welcome!?



P.S. This thread has been moved from Disk Array to HP 3PAR StoreServ Storage. - Hp forum Moderator



Failure is NOT an Option.
Dennis Handly
Acclaimed Contributor

Re: 3PAR VLUN Discrepancy

>if there is something that can be cleaned up at 3PAR CLI level relating to the VVset


The createvlun command allows you to specify the starting LUN.  Have you tried that?