Mirror Existing LUN

jpearcy · Thu Dec 16, 2010 7:29 pm

Is it possible to Mirror an Existing LUN. I could not find a way to do this. Also could not find a good walkthrough document on the subject.

Thu Dec 16, 2010 9:44 pm

Do you want mirror with off-line recovery or do you need synchronous mirror aka high availability?

jpearcy wrote:Is it possible to Mirror an Existing LUN. I could not find a way to do this. Also could not find a good walkthrough document on the subject.

jpearcy · Thu Dec 16, 2010 10:15 pm

remote site (DR) mirror.

Tue Dec 21, 2010 10:25 am

You can do this, however be sure that your DR does have at least 100Mbpsconnection.
1. Create an image file based target on the DR site (should be the same size as the current lun)
2. On the primary StarWind server create: Hard Disk->advanced ->Mirror (Raid1)->Create a MIR file->Select your LUN as a primary mirror(if using an image file target - remove the actual target and select it's image file rather then the whole target )->Select the DR mirror->initialize(synchronize mirrors)

jpearcy · Wed Dec 29, 2010 2:35 pm

So I am right clicking the target, and "remove Target" then building my primary mirrored lun using the IMG file that I just removed the target for. Then reattaching my server to that new mirrored LUN?

Tue Jan 04, 2011 11:02 am

To be maximum precise
1. remove the target "yourexistingtarget"
2. Create an image file based target (same size as the mirror) on the second server
3. Create a mirror which will use "yourexistingtarget" image file as the first mirror and the target from 2. as the second mirror.

jpearcy · Mon Jan 17, 2011 4:20 pm

Ok, one problem I see with mirroring is I cannot extend the size of the LUN once its a mirror. This is a big problem for us.

Tue Jan 18, 2011 8:42 am

Could you please try to describe your scenario with as much details as possible so we could try to find out right way for you to proceed. Thank you!

jpearcy wrote:Ok, one problem I see with mirroring is I cannot extend the size of the LUN once its a mirror. This is a big problem for us.

jpearcy · Tue Jan 18, 2011 12:28 pm

I have LUN mirroring turned on now. But I need to extend the size of the LUN. I cant find this option with a mirrored LUN. I see the option on other LUNs

Tue Jan 18, 2011 1:30 pm

I know this from your previous post. But to help you I (we) need to understand why you need to grow the LUN. Your StarWind usage scenario. Not sequence of actions you perform w/o positive result. Thanks!

jpearcy wrote:I have LUN mirroring turned on now. But I need to extend the size of the LUN. I cant find this option with a mirrored LUN. I see the option on other LUNs

Tue Jan 18, 2011 2:04 pm

jpearcy wrote:I have LUN mirroring turned on now. But I need to extend the size of the LUN. I cant find this option with a mirrored LUN. I see the option on other LUNs

I assume the other LUNs have basic functionality w/o being mirrored or taken snapshot of.
To extend LUN's size you will need to remove the Mirror device->recreate it as a simple image target-> grow it to the desired size and remove it from the management console-> grow the second mirror->recreate the Mirrored target->connect it back to the client

Tue Jan 18, 2011 2:56 pm

I don't think this is doable for user... Can we arrange the same sequence of actions from our side?

Max (staff) wrote:
jpearcy wrote:I have LUN mirroring turned on now. But I need to extend the size of the LUN. I cant find this option with a mirrored LUN. I see the option on other LUNs
I assume the other LUNs have basic functionality w/o being mirrored or taken snapshot of.
To extend LUN's size you will need to remove the Mirror device->recreate it as a simple image target-> grow it to the desired size and remove it from the management console-> grow the second mirror->recreate the Mirrored target->connect it back to the client