Perhaps you've forgotten but you can boot from the RecoveryHD partition.
There are a number of ways you can do this. Some of them depend a little on how brave you are and if you're prepared to use the command line?
One way is to boot from the RecoveryHD partition and clone the existing drive to an externally attached drive. Boot from the external drive and prepare the RAID that way. Do you really want a RAID though? You are aware you lose the ability to have a RecoveryHD parition once you configure a software RAID?
To me and depending on the circumstances having the RecoveryHD partition is actually a useful feature.
Another way is outlined in this support KB:
That helps a ton. Thanks!
We have a web application that runs on an older Mac Mini. The server is in dire need of an upgrade, including redundancy so failure is less likely.
Our plan is this: we have two brand new i7 Mini's w/10.8.1 server. We setup the 1st Mini with RAID 1 mirror, install the OS and webserver, then attach an external USB drive for Time Machine backups. (a side question, can Time Machine be configured to mount and backup to a network drive?)
The 2nd Mini will be a cold spare, if the 1st Mini dies we can simply swap in the cold spare Mini, restore the backup OS from Time Machine, and then we are good to go. Downtime will be minimal.
So yeah, we were thinking that RAID is good. But maybe it is overkill. We'll have Time Machine backups, and Time Machine really can restore a complete OS (it can, can't it?), then we may not need the RAID mirror? That way we can take advantage of the tools in the RecoveryHD partition?
What do you think?
". . . can Time Machine be configured to mount and backup to a network drive?"
Assuming I've understood your question and if the network drive can support it (Time Capsule etc), yes.
"We'll have Time Machine backups, and Time Machine really can restore a complete OS . . . it can, can't it?"
It can but for a critical server/services environment and IMO I would not trust it. There are many threads describing how restoring from a TM backup can result in disaster. Would you want to trust it if - when the worst happens and you absolutely need it - some or all of it is unusable?
I know you may have considered this but I mention this for others just in case they haven't. Any backup strategy should involve a scheduled test restore. Reading in between the lines of many of the threads made on these and other forums, there appears to be many who diligently perform regular backups day after day, year on year, yet have no 'guarantee' that any of it is usable because they've 'failed' to perform a worst case scenario restore.
Having said all that, TM for ML Server is supposed to be more reliable but for me it has always been and probably always will be a backup solution for single home users only. Which is was what it was designed for in the first place. Using it in an enterprise or critical services environment . . . I don't think so.
Other's no doubt may offer their own opinions and as in many things YMMV. The above is just my 2p.
Your help is excellent, thank you.
We have decided to go with RAID 1 mirror on the Mini. And we'll have TSM offsite backups. But I have one more question regarding setting up RAID:
"Another way is outlined in this support KB:
I'm a little confused by this link. It is clear on how to setup RAID. But installing the server (10.8.1) as described in the "Additional Steps" section talks about logging into the App Store and getting Mounton Lion installed from there. That is weird.I do not have an App Store account, nor do I want one. Is this suggesting that I'll need to buy 10.8.1 server from the App Store? It doesn't quite say that, but those instructions are vague.
After more digging, it appears that one can reinstall the complete ML server from the App Store without having the purchase it for $20, as long as you already purchased a Mac with the server software originally on it. All one really needs is a broadband connection and an App Store account. With that you can run RecoveryHD -> Reinstall OS X. That is why it is critical to create a non-RAID install on a USB flash drive before you RAID your Mini, so you can still run the Reinstall OS X utility from the RecoveryHD on the flash drive.
Am I understanding this correctly?
You can find a guide online on how to create bootable USB recovery media. After that you can format the drive to RAID 1 using Apple Disk Utility from the bootable drive.
Mountain Lion and OS X Server should appear in the Mac App Store, while logged into your Apple ID, under the purchases tab.
Download a copy of the Mountain Lion installer to create the USB recovery media. After performing the clean install you simply download OS X Server while logged in with your Apple ID on the Mac App Store.
That's all there is to installing OS X Server, it's just a download.
P.S. Performing a clean install will also recreate the Recovery HD partition automatically. This recovery partition on your Mac's HD doesn't contain the full operating system, just enough to download it again, so it might be a good idea to keep the USB drive around :-) Any time Apple updates OS X you can download the installer again from the App Store and it should be the latest version i.e. OS X v10.8.5