Usual Disclaimers apply – do this at your own risk, ensure you have complete backups first, and if you don’t understand something, don’t do it!
this has now failed, and despite and hour or two on the phone to apple plus several other attempts…it’s unbootable!! READ this to completion before attempting this on your own Lion server!
I recently deployed a brand new Mac Mini Server (MC936B/A) pre-install with Lion Server.
By default, the 500Gb ‘Server HD’ is the OS installation, and ‘Macintosh HD2′ is the second 500Gb disk, as 2 separate disks (no RAID setup)
Since we are using a couple of external 2Tb disks for Time Machine, the second internal drive would be better utilised as a RAID1 mirror, to reduce the likelihood of downtime.
I’ve read so many articles on the web about doing this, mostly pertaining to Snow Leopard Server (SLS). Many of them were incomplete, out of date or in some cases, wrong! There’s nothing publicly available on Apple’s website about how to do it, so I thought I’d write this.
Firstly – make sure you have a backup, or two, or more if you’re paranoid! I checked there was at least 1 fully up-to-date time machine disk, before shutting down the server.
What I used for doing this…
- 1x APC SmartUPS 750VA UPS
- 1x Firewire 800 Cable
- 1x iMac running Snow Leopard
- 1x Mac Mini Server running Lion
- 1x Monitor, USB keyboard and mouse for the Mac Mini
I put both machines on the UPS, simply because the power in the building can be a bit flaky, and a hard-poweroff during an array rebuild is never going to help matters.
This is based partly on instructions from Apple Support, and partly on community information from the web.
Process was as follows…
- Connect power from the UPS, and start up the iMac to desktop
- Start up the Mac Mini then goto Apple > System Preferences > Startup Disk
- Click the button which says ‘Target Disk Mode’
- Connect the firewire 800 cable from the iMac to the Mac Mini
- Click the ‘Restart in Target Disk Mode’ confirmation on the Mac Mini
- Wait for the Mac Mini to reboot, and show a big firewire symbol on the screen
- Start ‘Disk Utility’ from spotlight on the iMac
- Wait for the firewire disks to detect and show up in the list
Now, you should see all the disks showing up in Disk Utility.
First Job is to make a Disk Image, so you can always get back to where you are now!
Select ‘Server HD’ then click ‘New Image’ – save the image to the iMac’s local disk, and name it something like ‘ServerHD-20110803′ so you know when it was created.
Once that’s done (it only took about 5 minutes on this setup), you should ‘Verify Image’ to ensure it’s consistent and valid. In the left tab, select the ‘ServerHD-20110803.dmg’ image and select ‘Verify’, and do NOT interrupt this! You can also ‘mount’ the image (as with any DMG file), and check the contents of it in Finder, to reassure yourself the data really is all there. Unmount it when finished, and keep it safe in case you need to restore it later – hopefully you won’t though!
Now, let’s get started doing the actual RAID config work…
Back in Disk Utility, click on the partition for ‘Server HD’ and then click the ‘RAID’ tab on the right side.
It will say ‘Untitled RAID Set 1′ as the name; change this to ‘ServerRAID’ if you prefer. Check it’s using ‘Mac OS Extended (Journaled)’ and ‘Mirrored RAID Set’, then drag and drop ‘Server HD’ from the left tab into the white area on the right.
You will get a confirmation warning about creating the RAID set and information about doing it non-destructively. Click ‘Enable’ to enable the RAID set, which will now show up like this…
So, now you have an array with a single drive in it, not much use as it is, but on its way!
Now, drag and drop ‘Macintosh HD2′ underneath the existing RAID Slice in ‘Server HD – Mirrored RAID Set’… and you will see this…
Click ‘Rebuild’ which will wipe Macintosh HD2 and add it to the array as a blank drive.
Rather scarily, it will suddenly vanish from the list on the left – don’t panic that’s normal!
You can see at the bottom it’s ‘Adding booter for RAID partition disk3s2′ which is the new drive. That means if disk2 (the first in the array) fails, it can then boot from disk3 (second)
After a few seconds (up to 30 or so), you will see this appear…
This means it’s created the array, but then realised (correctly) there’s no data on the second disk, so it starts mirroring the entire disk ‘Server HD’ across to the new slice (previously ‘Macintosh HD2′). Estimates vary wildly on how long this will take, but on a 500Gb drive anything from 5 hours to 2 days is actually possible!
This dialog then appeared over the top of Disk Utility, which kindly estimates the rebuild at 14 hours!
On our iMac, Disk Utility then crashed and vanished! Start it back up again relaunched the windows and the array rebuild appeared to be continuing in the background anyway, but it took a good 10 minutes to re-estimate the time to completion.
You can also fire up a terminal window and run
diskutil appleRAID listto check the status of the rebuild that way, it’s sometimes easier to read than Disk Utility.
After 16 hours, the rebuild hasn’t finished – and is now estimating 2 days to completion… going to call apple about this now!
15 Minutes on the phone to Apple Care – they said it’s probably ok, as long as it’s still moving. If it stops changing completely, that would be bad! It’s now estimating 1 day 17 hours, I’m hoping that’s a very ‘outside estimate’!
Will update this posting once this is complete… at the moment it’s still doing the rebuild.
38-40h later – array rebuilt complete! Both drives online, all looks ok! Rebooted the mac mini….flashing question mark folder of death!! Great!! Reconnect ad target disk mode…array ok…but it won’t boot…more to follow later…
What I have learned from Apple Care so far…
- There’s no media available for Lion Server, no USB recovery, no DVD recovery
- You can boot using Alt+Cmd+R to use ‘Internet Recovery’ whereby the firmware boots from an image on apple’s servers on the Internet!
- When using RAID – you can’t have a local recovery partition (unconfirmed so far)
No comments:
Post a Comment