Barriers to Storage

[RParker]

I know with ESX 3.5 there were problems getting RDM's to work, but now with ESX 4.0, I guess I expect too much.

I have a plain 16TB device, no frills no SAN, it's just a Fibre card in a big box with 16 SATA disks, basically. So how do I add RDM to ESX to see it as 16TB RAW space?

I rescan, ESX 'sees' the storage, but I can't use it, because I am limited to 2TB (STILL). So I create a VM and point to this space as RDM, but I get an error 'vmdk is larger than maximum size supported by the datastore'.

OK, so now what? I have to create 8 2TB devices and keep using extents to get the space I want? I have tried every combination (except for maybe the one I am overlooking) on how to ADD 16TB of space to a VM so I can configure it for use in Data Recovery, that's it. Or are we stuck using only 2TB of space for that too?

I can't configure the storage (on ESX) for a datastore because I can't get around the 2TB limit (why this is STILL 2TB is truly astounding), and RDM appears to need a pointer with enough space to map to RDM, so what are my options now?

[AntonVZhbankov · Accepted solution]

The only way to use 16TB of space in VM - is to add 8 RDMs or VMDKs 2TB each.

Or, if you plan to use iSCSI, connect 16TB LUN with software initiator from inside guest OS.

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VMware vExpert '2009

http://blog.vadmin.ru

[RParker]

The only way to use 16TB of space in VM - is to add 8 RDMs or VMDKs 2TB each.

well honestly speaking, does that make any sense to you? I can go buy a 2.5TB disk. Performance issues aside, if I want to use a disk to do backups or put a 2.5TB VM on it, I should be able to? Or am I just too idealistic? That's insane.

Well anyway, the documentation clearly states for Data Recovery that you must attach the storage via ESX (storage) in order to get the Data Recovery to use external storage and not the VM. But it's not entirely true.

I have been dealing with this for 6 hours now, and I am about at the end of my rope, FINALLY Windows saved the day. When you configure the VMDR you have the option during setup to use a Windows share.

Since WINDOWS isn't limited to less than 136TB of RAW space, I can use any amount of space however I want, because I can point the appliance to a windows share, done!

So that's what I am doing. Say whatever you want, Linux / NFS limitations or Windows share no limits... Gee, umm.. I will take configuration options please!

Thanks Anton, for your help. Not just this but many other posts. You are definitely a value to these forums.

[AntonVZhbankov]

Oh, it's a liitle late here, i just missed whom I reply to... and missed a half of your post.

Actually it makes little sense to me that there is still 2TB limit on LUN size on enterprise virtualization platform and we already have 2TB of storage space in a single disk. I completely agree with you here. ESX is now 64bit (6 years after first 64bit x86 CPU), so I suppose we can wait for 128TB LUN in hmm... 2012.

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VMware vExpert '2009

http://blog.vadmin.ru