1thumb
2 Iron

How do I track unused storage on a host and reclaim it

Is there any way to query an array to find unused storage that has been allocated to a server whether it is physical or virtual and reclaim it?  I will be looking for this capability on VMAX, DMX, Clariion, VNX.

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sauravrohilla
4 Tellurium

Re: How do I track unused storage on a host and reclaim it

Ionix Storage Scopre does it. There is no single command to find this. You probably have to write a script to find the unused storage allocated to each server. Or if any one has a better way to find it

regards,

Saurabh

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jet_pilot
2 Bronze

Re: How do I track unused storage on a host and reclaim it

Try using "symcfg -sid 1234 show -pool ThinPoolName -thin -all -detail -mb".  Repeat for each thin pool.  Search the aggregate output for the TDEV(s) that you're interested in to determine how much real storage is consumed by that TDEV in each pool.  As the other commentator mentioned, this is likely something you'll want to script.
As for reclaiming unused TDEV space there are a couple of options.  First, try this command... symconfigure -sid 1234 -cmd "start free on tdev 0abc type=reclaim;".  The "reclaim" parameter will cause the VMAX to reclaim pre-allocated thin blocks marked "never written by host" plus any blocks found to contain all zeroes.  All major operating systems offer utilties that will fill unused logical disk space with zeroes in preparation for this type of space reclamation.
As an alternative, try using "type=unwritten" instead of "type=reclaim", which will only recover TDEV blocks marked "never written by host" leaving zero-filled blocks untouched.  Caution: there some instances where you do not want to reclaim zero-filled space; refer to EMC white papers for specific examples.
Finally, if you ask your EMC Technology Consultant real nice he'll be able to get you a copy of an EMC utility called StorReclaim.  StorReclaim is a Windows utility run on the server.  It examines the VMAX disk assigned to the server and then sends a list of unused blocks to the VMAX which the VMAX then reclaims.  The unused space does not have to be zero-filled when using StorReclaim.
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