equallogic question

[wb2]

I'm prepping my physical server for conversion to be a vmware esxi4.1 VM.  It's a file server and currently the data drives are on a fiber channel san.  I'm planning out how I'm going to move 3TB worth of data on to an iscsi san prior to the VM conversion.  Then I'll use iscsi initiator to access the 3TB volume.  To get the 3TB moved over I was thinking of using Windows 2003 dynamic disks to create a volume so I could simply mirror the fc san to the iscsi san drive, then break the mirror and continue on with the mirrored copy that sits on the iscsi san.  So this all relies on having the disk converted to "dynamic disks" in Windows.  My big question is, will a "dynamic disk" cause problems in either VMware or my Equallogic SAN?

[AndreTheGiant]

Dynamic disks are not recomented.

You can use robocopy to make a mirror of two disks.

Andre

[wb2]

I've considered robocopy and I believe it cause me a lot of headaches.  With issues, such as open files, and problems getting all NTFS ownership info, etc I decided not to use that solution.  It'll just take too long.  That's why I was looking for some sort of drive mirroring solution.  Are there any articles which show dynamic disks failing or causing any other problems you are aware of?

[AndreTheGiant]

They are just not recommended... but they work.

In a couple of cases I have some VM with this type of disks and I do not have particular issues.

Andre

[wb2]

andre, when you say not recommended, is that from a vmware point of view or Equallogic san point of view?

[sketchy00 · Accepted solution]

I've found (as well as others) Robocopy to behave odd on anything newer than Windows Server 2003.  Since this is raw data, perhaps just a tape backup/tape restore might be most appropriate.  You'll have the benefit of pretty decent backup speeds to get it off onto tape (or temporary disk), then do a restore to an alternate target.  That way it would be able to do consistency checks, and preserve permissions, etc.

[wb2]

I considered the normal backup/restore.  But with the size of volumes I need to move it would take about 50 hours of downtime.  I think I'll go with the dynamic disk approach, mirror, then break the mirror.  All done, only a couple minutes of downtime.

[IRIX201110141]

Along time ago i learned that using dynamic disks within W2k3 which coming through the iSCSI Initiator is not allowed and will causing trouble. Take a look to http://www.equallogic.com/uploadedfiles/Resources/Tech_Reports/tr1015-ms-windows-2003.pdf (Page 9).

About migrating i can say that we have converted a 4.2TB Netware Fileserver into a Windows 2008 VM by using robocopy/vice versa[1]. But every volume was below 2TB and we can stay with VMDKs. We performing a pre-copy during the week and on a sunny weekend we just copying the last delta and pull the cable out of the old netware machine (R.I.P).

With customers which alreay using MS DFS we use the File Replication feature for syncing the files into a new fresh W2k8 VM.

[1]. Be careful with path lenghts with more than 255 chars

Regards
Joerg

[AndreTheGiant]

when you say not recommended, is that from a vmware point of view or Equallogic san point of view?

Both... and also from Microsoft point of view

Andre

[wb2]

I did some more research.  iscsi initiator with dynamic disks is not the way to go.  Too risky.  I'll probably use our backup software to copy everything over.

[Dr_Virt]

Is this an AD integrated site?

We have successfully done this with DFS. Build a new server, remap drives with a script, and migrate behind the scene.