How to Setup a RAID 1 in Mac OS X Lion Server

Scribbled by Lethal Illness @ 5:14 PM on July 31st, 2011.

I’ve told you why I’m not upgrading my MacBook Pro to Lion, though I’ve recently bought the new Mac Mini Server for Desoulbel’s future web server. I assumed (making an ass out of myself and Apple) that since there are two 500GB internal hard drives inside of a SERVER that they would automatically be configured in a RAID [Redundant Array of Independent Disks] 1. RAID 1 is the configuration of one or more hard drives mirroring another. While they say RAID 1 isn’t a form of backup in this case it is a backup if my hard drive crashes or bums out so that I don’t lose all the data and get sued by clients. Though this isn’t necessarily the most ideal tools for backups for common people and computers because if there is a fire, the unit is stolen, or coincidentally both drives die then you are basically fucked without anyway to retrieve your data. So what is the big deal with installing a RAID 1 configuration in Lion and why don’t we just do it the same as in Snow Leopard? Because Apple has decided not to provide restore disks or USB drives with the OS – leaving it up to the Mac App Store or a hidden partition of Lion recovery. I personally don’t want to go out on a gamble and risk the OS coming back through an internet connection and hope everything is magically okay. I figured out a way to do it that requires no disks and no reinstalling of the OS. Though, it will take some time and a few tools you most likely have or can get for cheap.

Tools Required
Two hard drives that you want to put in the RAID 1, either external or internal.
An external hard drive.
A registered copy of SuperDuper!
A few hours and/or something to do to pass the long down time.

Before You Begin

You have to realize two things in this process before you can begin. The first problem you might have is backing up your extra data. Let me explain what I mean before this gets confusing. If you are doing this straight out of the box like me there is no need to worry about anything. This will work without having to reinstall a thing and with no hiccups (I just did this last night). Though, say you are doing this with a spare hard drive that you had lying around that you want to put in your regular Mac Mini or in your MacBook Pro by replacing the optical drive. If there is any data on that spare drive you need to back it up prior to following my guide with an additional external drive not including the one you will need for this process. This data will not be able to stay on that hard drive while doing this procedure.

Secondly, you need to understand this RAID 1 works in a pair. Whatever is on one drive will be exactly on the other. So say we create our RAID 1 with a 300GB drive and a 500GB drive. Your RAID 1 setup will be the total size of 300GB – meaning the leftover 200GB [on the 500GB drive] is wasted and you cannot store anything in the extra space, no exceptions. Again, doing this out of the box like I am this is definitely not a problem and you can move right on to the first step being Apple gives you two identical drives.

Additionally, I need to add this little disclaimer. This is my personal experience with my method. It worked 100% with no hiccups, problems, or dilemma for me, but because of the so many variables in hardware and technology these days I cannot guarantee my experience will 100% be yours. Though, I am very confident this will work for you as it did for me, there is always that slight chance it will not. I am not to be held responsible for anything that happens or breaks.

Backing up the OS Drive

When the RAID 1 is created, it will need to rebuild (sync) the drives. When the RAID 1 rebuilds it will wipe both of the drives in their entirety for a clean start. Since the OS and applications (including the Server app) are on one of the hard drives we will need to back up the main hard drive so that everything doesn’t have to be reinstalled. In my case, the hard drive with the OS installed was “Server HD” and I will be referring to it as that, though yours can differ. In order to back up Server HD, you will need to open up SuperDuper! and plug in your external hard drive. Do note: that the external hard drive does not need to be the same size as your Server HD though it just needs to have enough space to store the amount you have it filled on the Server HD (in my case, out of the box there was only around 9GB taken). In SuperDuper!’s first dropdown at the top after the word “Copy” you’re going to select Server HD, while after “to” your going to want to select your external hard drive in the second dropdown. Leave the dropdown next to “using” as “Backup – all files”. Below in the white box, hit the “Options…” and follow these settings; leave the setting under “Before copy” unchecked. The default setting under “During copy” should be “Erase , then copy files from Server HD “. Finally, on under “On successful completion” choose from the dropdown “Set as Startup Disk”. The last setting will make the OS boot from the external drive without having to hold buttons when it starts up. All you have to do from here is hit the “OK” button to get out of the options and then “Copy Now” button and confirm you want to copy. It took about 20 minutes for mine to complete the process, though this will depend on the amount of data on your drive.

Settings to transfer Server HD to External Drive.

Zeroing out the Disks

After Server HD is backed up into a bootable drive [on our external hard drive] we will need to erase both of the hard drives we would like in our RAID configuration. This is an extra step that will make sure there is no spare data on your hard drives to mess up your RAID 1 configuration. We are going to need to open up the Disk Utility and select our Server HD drive from the left panel. To the right you are going to need the tab that says “Erase”. We are going to leave the format as the default “Mac OS Extended (Journaled)” and name the hard drive whatever you’d like (I left mine Server HD). Next we are going hit the button that says “Security Options” and move the slider right by one and hit “OK”. After that above the same button for the security options it should say “Erase option: Zero Out Data selected”. From here we just hit the button that says “Erase…”. After that it will take about an hour or so, so you might want to play some Call of Duty or watch a movie to kill the time and check back later.

This is what your settings screen should look like prior to hitting erase.

After the Server HD is zeroed out we are going to need to zero out our second drive we want in the RAID 1 configuration. Even though I didn’t put anything on the second internal drive I zeroed out this drive as well just to be sure. All you have to do is repeat the steps above after clicking on the second hard drive in the left side panel. In my case, the second hard drive I was using without the OS was “Macintosh HD2″ and I will be referring to it as that, though yours can differ. Be sure that you select the right drive and not your external – else you will be screwed! Again after following the steps above you are going to need to wait another hour our so.

Configuring a RAID 1

Now that we are all zeroed out we are ready to begin configuring our RAID 1! Select the Server HD drive on the left panel in the Disk Utility. To the right you will need to hit the “RAID” tab this time. Underneath the tabs, next to “RAID Set Name:” enter in the name you desire this setup to be called. Since I liked the idea of the drives being called server; I named my setup “Server RAID”. Next, we are going to leave the volume format at “Mac OS Extended (Journaled)”. Since we are setting up RAID 1 we are going to put the “RAID Type:” to “Mirrored RAID Set”. Next we need to setup some more options and to do so we need to click the button that says “Options…”. Your first option should ask the “RAID Block Size:”. From what I understand, this is going to be the amount we are going to be writing the most frequent to the drive in order to preserve the most speed we can. Since my server is going to be used as a full blown web server with databases I left it at 32K. Though, if you will frequently be using your server for video or bigger files then you should set your block size higher accordingly. The second option is a check box that asks if you want to “automatically rebuild RAID mirror set”. Basically, if the drive goes out of sync due to failure/replacement of one drive, being shutdown improperly, a power surge, etc. it will rebuild and sync the drives so that there is no problems. They say checking this could slow down your drives when they need to rebuilt but so will running any type of back up so it’s not a big deal. After these options are done you can click the “OK” button and hit the + button. You should now see the name of your RAID in the box above.

From here it gets even easier. Drag both of the drives we want to be configured on top of the name of our RAID in the white box. You should see a little arrow on top of the RAID when you mouseover while dragging. After dragging each one, you should see them below the name of our RAID similar to the picture below.

This is what you should see after dragging both drives to the Server RAID.

After this we are ready to create our RAID 1 configuration. Just click the “Create” button and let the drives setup and rebuild. This took only a few minutes for me which is probably thanks to the step we took to zero out the drives earlier.

Restoring Our OS

We certainly don’t want to have to boot off of our external drive forever right? I mean that would defeat a lot of the purpose of setting up the RAID 1 in the first place. So we need to restore the OS without overwriting all our RAID settings. Luckily, SuperDuper! contains a special function over its competitors called “Smart Update”. Please note: the Smart Update feature is only available to those that have the purchased/registered edition of SuperDuper! and you can not do without. It is only $28 if you can afford it, but if not it is available through other resources like torrenting/pirating. Though if you do the torrenting method you should purchase the legit version when you get the money and support the developer. Similar to our first steps of backing up our OS drive, in the first dropdown next to “Copy” we are going to select our external drive. The second dropdown next to “to” should have our new RAID setup selected, which is in my case Server RAID. We are going to want to go back to our options in SuperDuper! and this time follow these settings; Again, leave the box unchecked under “Before copy”. Under “During copy”, we will want to select “Smart Update Server RAID from “. Lastly, under “On successful completion” we are going to want to set our RAID back as the startup disk by choosing “Set Server RAID as Startup Disk”. After choosing the appropriate settings hit “OK”, “Copy Now” and confirm you want to copy. This should take a shorter amount of time then the first copy in the first step as mine was around 12 minutes this time, though it will also vary upon the amount of data you are coping.

SuperDuper! settings from External to Server RAID | SuperDuper! in progress

Wrapping Up

After all this is said and done, all we need to do is restart Lion and after you are safe to eject your external hard drive and enjoy the comforting benefit of knowing your data is redundant. The process isn’t as complicated as it sounds from first glance. This was all done on my first attempt from a hunch I figured would work and it did thankfully. The process is a little time consuming, but I would imagine reinstalling the Lion all over again from the Internet might take longer then two transfers back and forth over an external hard drive.

Please, if anyone has any problems or needs me to make things more concise do not hesitate to drop a comment below.