HPE Storage Users Group

A Storage Administrator Community




Post new topic Reply to topic  [ 5 posts ] 
Author Message
 Post subject: SCSI Unmap on Phys Mode RDM's?
PostPosted: Wed May 28, 2014 9:17 am 

Joined: Sun Oct 14, 2012 7:55 pm
Posts: 3
Is it possible to perform SCSI unmap agasint a 3PAR LUN in VMware assigned setup in Physical Compatibility Mode? We use 3PAR Recovery Manager for Exchange, and Physical compatibility mode was setup for this to function.

I've done vmfs unmap -u on VMFS Datastores successfully, but cannot locate how to reclaim dead space on a 3PAR RDM in VMware.

Let me follow by saying that SDelete used to work back when we were on ESXi 4.1 and 3PAR InForm 2.3.1, but now that we've upgraded to ESXi 5.1 and 5.5 with InForm 3.1.2 (MU1), the SDelete tool inside the Guest VM no longer reclaims space at all. Not sure what's going on there.

_________________
Kelly


Top
 Profile  
Reply with quote  
 Post subject: Re: SCSI Unmap on Phys Mode RDM's?
PostPosted: Wed May 28, 2014 5:40 pm 

Joined: Mon May 26, 2014 7:15 am
Posts: 237
Hmmm, never tried this, but how I think it should work in my head is that there no point in running the UNMAP command in VMware as an drum is simply a pointer file, nothing more so it's only taking up kb on the vmfs datastore, especially with physical mode, VMware has no control over it at all, it's simply a facilitator to pass it through to the vm.

I can see sdelete working, have you tried some different switches on the command, isn't there a -c and -z?

I think it's the -c option you need....possibly....I always get confused between the two, especially as you would think -z stands for zero, but it think it's the other way around.


Top
 Profile  
Reply with quote  
 Post subject: Re: SCSI Unmap on Phys Mode RDM's?
PostPosted: Tue Jul 22, 2014 1:58 am 

Joined: Fri Jun 27, 2014 2:01 am
Posts: 390
The reclaim process for "reserved" space has changed. Used space is still reclaim quite quickly but reserved space on 3.1.2 could take some days to be reclaimed...


Top
 Profile  
Reply with quote  
 Post subject: Re: SCSI Unmap on Phys Mode RDM's?
PostPosted: Tue Jul 22, 2014 5:30 am 

Joined: Wed Oct 30, 2013 2:30 pm
Posts: 242
Running a t10 unmap today on a p mode rdm unfortunately doesn't work in vmware (this is the one area that I think hyper-v has vmware by the balls, because it does work on a vhdx).

The reason is that while it is true that the pRDM is simply a pointer file, it is a pointer file attached to the vmware SCSI controller, so it's not exactly the same thing.

Supposedly I have heard that vmware is working on this now that red hat and windows support t10 unmap.

Sdelete should work. I've used it inside vms against my 3.1.2 7200's many times


Top
 Profile  
Reply with quote  
 Post subject: Re: SCSI Unmap on Phys Mode RDM's?
PostPosted: Fri Jul 25, 2014 11:21 am 
User avatar

Joined: Fri Jun 21, 2013 1:03 pm
Posts: 113
Location: USA
Beyond the array there is an OS dependency, what is the guest OS and filesystem used?


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 


Who is online

Users browsing this forum: Google [Bot] and 42 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group | DVGFX2 by: Matt