RAID on Mac mini Server (2011 i7)

I foolishly wiped my two drives and mirrored them together about 6 hours ago. I've just completed my 5th 45-minute long attempt at reinstalling Lion Server from the web and I got the same error as before:

"Can't download the additional components needed to install Mac OS X. Check your Internet connection and try again."

Of course, my internet connection works just fine. I can only imagine their servers are swamped and cannot serve up some critical files. Now my next best option is to take my brand new machine to the mac store to have them reinstall the OS.

This is a crying shame. Apple, you need to provide backup media.

Okay, after much hassle and a myriad of other errors, I decided to give up on the mirrored drive setup and go back to JBOD. Of course, as soon as I did that, it worked perfectly. Apparently the current version of the OSX web installer can't handle RAID installs.

Once I'm happy with my machine, I'll create a disk image and then re-attempt the RAID mirror.

ideelist,

I finally got it working. Well, kinda. I had to break the RAID array and then the reinstall worked like a charm the very first time. It would seem there is some sort of bug when trying to do the web instal on a mirrored set.

I'll just have to get the box set up the way I want, create a time machine backup, then set up the RAID and restore the backup.

Also be aware that if using Raid, you can't use the Diskutil GUI tools for actions such as verify or repair of permissions. This has to be done from a Terminal command line.

sudo diskutil verifyPermissions <Disk Device>

sudo diskutil repairPermissions <Disk Device>

I found the basic principle on another forum thanks to a guy called 'e-whizz' and this what I did to make RAID 1 work on a mac mini server with LION server.

You can easily configure the second drive on a mac mini server for a Mirrored RAID 1 set with Lion Server without either reinstalling or erasing your existing setup.

The initial setup process takes about 30 minutes, though the rebuilding of the mirror disk will take several hours, depending on the amount of data you have on the drive. It took around 3 hours on a new mac mini server with lion server installed, nothing else configured.

Before you start, please ensure you have a current backup of the server. Getting the following commands wrong can render you server unusable.

What you need to use is the command line version of Disk Utility, diskutil.

Before you start, clone the hard drive. You can use SuperDuper (or similar, I have used SuperDuper) with copying all files onto a USB memory stick. If Lion is freshly installed, 8Gb will do. SuperDuper will create a bootable copy on the USB.

Boot the mac mini from the external USB. To do that, reboot and hold down the option key while restarting. You will see a window, select the USB drive to boot from.

Launch the terminal and type the following command:

diskutil list

This gives you a list of all the drives and partitions your system knows about.

You need to find the Server HD partition (the first disk) and the HD2 partitions (the second disk). These are the two main ~500GB drives. You will be using the disk IDENTIFIERs when issuing the diskutil commands. For a stock standard Mac Mini Server, the commands below are correct, but if you have previously changed the volume names, or repartitioned at any stage the disk identifiers and volume names may differ.

First enable RAID mirroring on existing Server HD volume. This will create a single disk, unpaired mirror, without affecting your data.

Using this syntax:

diskutil appleRAID enable mirror disktomirror

where disktomirror is your disk identifier for Server HD

On my mac mini server, Server HD was disk0s2, so I used this command:

diskutil appleRAID enable mirror disk0s2

You now need to run diskutil list again to see the disk identifier for the new RAID volume. The new RAID volume will be listed as disk# on its own at the bottom of the list.

On my mac mini server this was disk3 (disk 2 was the USB I booted from, disk 0 the first disk and disk 1 the second disk)

Next add the disk HD2 to the Server HD raid mirror volume (on my mac, as I said before, this is disk3) as a new member.

This step will erase disk HD2 and begin an auto repair of the Server HD.

Using this syntax:

diskutil appleRAID add member newdisk raidvolume

replacing newdisk and raidvolume with your particular disk identifiers

On my server this was:

diskutil appleRAID add member disk1s2 disk3

To follow the progress of rebuilding the mirror set, type

diskutil list

It will show you the progress in % of the rebuilding under status

Once finished, reboot and your RAID 1 is up and running and you have also a working backup on your USB (coz' that's where you booted from ;-)

After reboot you can check the status of your RAID with

diskutil appleRAID list

Both drives should show ONLINE under status, interestingly, the device node for the RAID changed on my mac mini server from disk3 to disk2

That's it

Just make an install USB Flash Drive, reboot server. Utilise Disk Utility to format drives into which variant of RAID you require.

This allows one to place Xcode and other necessities within install key.

This of course if after you have Time Machined your original setup if you require whatever Apple installed.

But, iLife would register as you own it, so App Store will allow you to re-install, as for Recovery Drive. If you have Time Machined drive what is need for?

One word of advice make key from fresh download of iINSTALL LION, it is in Application Folder. Once initialised it is gone as is LION SERVER install.

But, as above, once purchased App Store knows this, and lets one re-download.

Cheers!

`RobD...

Thanks for these steps. I followed them, but what I did instead of doing a full install was take a Time Machine backup first, then created the raid0 via Command+R. Afterwards, I exited the Disk Utility and went to the Restore from Time Machine.

This way, I didn't need to re-setup the server nor have to worry about the download failing.

Here is something that will work.

Before doing anything other than the original power up of

the new server and the nonsense that involves, you can do

te following to make a machine specific clone with recovery

drive.

1. Get a USB or Firewire drive. Repartition it GUID and

with one volume 1 GB and a second volume whatever.

2. On the Mini Server, open terminal and type in the following:

defaults write com.apple.DiskUtility DUDebugMenuEnabled 1

This enables the debug in Disk Utility.

3. Open disk utility and in the debug menu select show all partitions.

The Recovery HD shoul be seen grayed out. Select and mount it.

Next select restore option. It should be shown as source, if not drag

it there. Next drag the 1 GB partition created on the external drive

to destination. Then click restore.

Actually, at this point you have an exact duplicate of all the files

preset on the Recovery HD. This will be machine specific.

There is another method where you extract a DMG, but this creates

a generic Recovery HD which may not work.

4. You can use the Restore to clone the actual Lion install the the remaining

partition in the same way. Or, use your favorite cloning software.

5. Then you can do as you wish with the internal drives and still have a bootable

Recovery HD and system HD, which is "pristine".

That worked perfectly. No more recovery partition, but I'll just keep the Lion recovery USB stick for future use.

I set up RAID 0/striped and then reinstalled from Time Capsule. Took about 2 hours to recover 100GB, it booted and works fine. I didn't benchmark before/after, but definitely faster boot.

Thanks

Hi there,

I would be please if anyone could tell me if a full factory-restore is possible after going for the Raid 0 config?

Would this work you think:

Internet Recovery > Disk Utility > Delete Raid and set HD back to normal > Install Lion from download

If the Internet install re-create the recovery partiton evrything should be back to normal. Question is, does it work this way?

I have, just this evening, finished restoring Lion Server from Internet Recovery, to a RAID1 setup on a Lion Server (Core i7, August 2011).

Decided, following instructions on the web and apple care's advice, to use the GUI (Disk Utility) to build the RAID1 array, using a second Mac, and by putting the Mac Mini into Target Disk Mode.

Once the array had rebuilt (having been degraded upon adding the second (blank) disk), the diskutil command line AND the GUI, both reported "Online" for both disks. This was after nearly 40 hours by the way people … yep … 40 hours to rebuild 500Gb!

Rebooted the Mac Mini … DEAD. Flashing folder with question mark of death on it. No recognised operating system apparently this means!

Bought the Mac Mini to a faster Internet connection to try with Cmd+R for Internet Recovery, and re-installed Lion Server. This is where it got even more curious…

It re-installs, which took about 4 hours in total, and then boots up as if it's virgin 'out of the box'. So it asks for company name, etc etc. but no usernames?! Then it gives me a login prompt .. having NOT asked for a username!

I try the previously working admin account, hey presto, in we get! Launch Server.app … hmm… several of the services are still running as before. All the users are still there, all the groups are still there. The sharepoints have gone, but re-adding them maintains their original mount permissions. The Wiki is reporting 'Error Reading Settings' - kinda helpful, but also NOT helpful in any way!

So re-installing doesn't do exactly what I'd expected, but hey.. it's somewhere close!?

Now the dilemma … do I restore from the previous time machine backup … or do I leave it as it is now?

Apple … are DVDs really THAT expensive that when buying a machine for around £1000 you can't provide media with it? Seriously… on a BT broadband line in the UK the Mac was estimating about 12 hours to re-install the OS, that's assuming the line stays up for that long, which is not a given in some places! Progress?

To cut a long story short

OSX LION is not installable on a OSX LION SOFTWARE RAID.

I tried striped and concatenated. No chance.

I used a 1 GB USB stick to backup the recovery drive/partition. After that I followed the steps in the first post and configured Raid 0 (striped), installed Lion, both from a TimeMachine backup and from Internet (just to verify both ways). I can only tell that it worked like a charm either way.

I also tried to restore the two HDDs to their former state (separate) using Disk Utility on my USB stick. That also worked without any problems.

Sorry! I just noticed that you had wrote "Software Raid". My answer does only cover the non software Raid.