Redundant Array of Independent Servers
Since Apple stopped selling the Xserve on January 31, 2011, Server rooms are faced with a devil's bargain: the powerful Mac Pro server config has great performance and the Mac mini server has great economy and both make nice servers. But neither was designed as a rack-mountable modular system with available parts kits.
A possible solution is the R.A.I.S. suggested on
Take one Mac mini server configure as you like and enable its boot drive as a RAID member.
Boot the other Mac mini server into Target Disk Mode.
Connect them with a FW-800 cable (or ThunderBolt cable if the equipment supports it).
Add the TDM mini to the mirror that the boot drive is in.
Now if Mac mini #1 has blown a logic board, power supply, or drive you simply disconnect the FireWire cable and start up mini #2 without Target Disc Mode.
Voila! Redundancy! Costs less than an Xserve spare parts kit, too!
Resources | Comments | Test Results
This web page provides some resources for getting your RAIS together.
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SoftRAID 4 - Offers email notifications and faster rebuilds than Apple Disk Utility
Squashed Software RAID Monitor - Email notifications for Apple Disk Utility RAID mirrors
Mac HelpMate - Mac HelpMate Also Has Over 200 Maintenance Tools and Proactive Alerts
Watchman Monitoring - Mac focused plugins detect potential issues, report details and configuration information to reduce troubleshooting tim
iStat Server - iStat Server for Mac transmits your computer or server’s vital statistics to iStat for iOS.
CopperEgg Web Server Monitoring - CopperEgg website monitoring allows you to see system uptime, health and response time instantly.
Mac Mini Vault - - Data center with cabinets that fit over 140 minis. Power controls included w/ plans.
Green Mini host - Hosting provider that takes only Mac mini's, based in The Netherlands
Target Disk Mode
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In reverse chronological order
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- 10/20/13 8:47 AM
Gary Foster submitted this photo of the T-Key dongle he made using a WD Passport drive case as an enclosure.
Gary Foster's "T" key dongle in a WD Passport case
- 11/27/12 3:42 PM
I built a USB "T" key dongle and housed it in an old Apple Pro Mouse casing. Plug this sucker into any Mac, turn it on and WHAMO! instant Target Disk Mode. As long as this dingus is plugged in it is TDI all the time!
Home-made USB "T" key dongle
- 10/14/12 9:15 AM
Mountain Lion RAIS!
Two Mac mini servers with SSDs mirrored using SoftRAID 4.33. Unlike my experiences with Lion and earliers SoftRAIDs this boots when mirrored either through Thunderbolt or FireWire. However, I am using FireWire to isolate the mirror from the Promise Pegasus RAID array and the backup drives which will all be Thunderbolt interface.
Here are the steps I took:
1) Set up the first machine (without launching the Server app yet), give it an Apple ID account for the App Store and update it to Mountain Lion 10.8.2 and Server App 2.1.1. (Still don't launch server app).
2) Download Apple's Recovery Disk Assistant and create a recovery disk on a USB key (since RAIDing will get rid of Recovery Disk on the SSD.
3) Boot from a TDM utility drive and image the computer to an external drive - Just in case.
4) While booted from the TDM utility drive, install SoftRAID drivers and convert the SSD to SoftRAID.
5) Boot from the first Mac mini and TDM the second one using Thunderbolt (for maximum mirroring speed)
6) Initialize the TDM mini to SoftRAID and use the empty volume to convert the boot drive to a SoftRAID mirror. (Using Thunderbolt took about half the time of FireWire!).
7) Shut down the first mini and connect the TDM to it via FireWire instead of Thunderbolt
8) Hook up the Pegasus via Thunderbolt and voila!
Mountain Lion RAIS 2012.pdf
- 11/14/11 6:13 PM
Lion R.A.I.S. with SoftRAID 4.0.7 !!
Okay, having now used SoftRAID, I would have to say that trying to do a R.A.I.S. without it is crazy.
For one thing, you can install Lion to a single Apple formatted drive and not get the Recovery HD error.
Then you can convert it to a SoftRAID format and mirror it to your TDMac.
Pulling the plug on the Target Disk mode Mac to degrade the RAID was not a problem: SoftRAID rebuilt automatically and it only took TWO MINUTES whereas the Apple formatted software RAID required 8+ HOURS to rebuild.
With SoftRAID you can even add ANOTHER mirror. So if you have used the FireWire port for your TD Mac mirror you can add a USB/FW800 drive to the USB port, make it a mirror and then if one computer or the other blows up you can send it off for repair and replacement and maintain a mirror all the time just by popping that USB drive into the empty FireWire port (for best performance of course).
(With the new Thunderbolt minis your FireWire port would be available for the external drive all the time.
Add SoftRAID to the recipe book!
- 11/12/11 12:46 PM
Lion FireWire RAIS !!
The primary was a first gen Mac mini server starting with Snow Leopard Server. The Target Disk was a regular 2.0GHz Core2Duo Mac mini with a 500 GB drive in it.
The Snow Leopard mirrored RAID COULD NOT be upgraded to Lion because the Lion Installer would not create a Recovery HD partition on a RAIDed disk set. What a pain!
I deleted the RAID set - which created two disks with Snow Leopard server on them. Then I upgraded one of the to Lion Server with an App Store upgrade. When I had a working Lion boot drive, I started from an external drive and mirrored the other mini server hard drive to the Target Disk mode computer's drive. (I made sure to choose the Option to automatically Rebuild the RAID).
Then I cloned the Lion Server to the RAIS RAID and made it the Boot drive.
Once I had a working Lion RAIS I updated it to 10.7.2 Server - no problem.
Then I pulled the power cords out of each computer. I started up the Target Disk holding the T key and then booted the Mac mini Server and it booted. However, the RAID was still intact!
So I pulled the power cord from the Target Disk Mode computer and made sure I had a degraded RAID.
Without restarting the server I started up the Target Disk Mode Mac mini using the T key and on the Server using Disk Utility I observed that the RAID was already rebuilding --without requiring a restart of the Server.
- 8/20/11 10:26 AM
I used older Mac minis running 10.6.8 Client (since the oldest was a core solo and could not support Lion).
The target disk mini was a core solo with a 32 GB SSD in it. (No extra fan noise in TD mode).
The primary mini was a 2 GHz Core 2 Duo with a 200 GB drive in that was formatted into two partitions.
First partition was set at 31.7 GB to match the target disk mode size. Second partition was the remainder.
Booted primary off a CD. RAID mirrored the target disk to the primary (selecting the Option to automatically rebuild) and installed 10.6.3 and updated to 10.6.8.
Connected to ARD and Logmein for testing.
Pulled the power cord out of the primary so it died.
Pulled the Firewire cable out of the Target Disk mini and powered it off.
Turned on the Target Disk mini and it immediately booted. Whole operation took two minutes.
It was reachable by ARD and Logmein (although I had to log out of Logmein and back in to the website first).
Then I shut Down the Target Disk mini and started it up in Target Disk mode again.
I plugged in the FireWire cable and turned on the primary mini again.
The primary mini booted up and immediately began rebuilding the mirror!
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This page last modified: Monday, March 3, 2014 | 12041 visitors.
Warning: No warrantee of the RAIS concept or its fitness for use is express or implied. Apple, Mac mini, and Mac OS X Server are trademarks of Apple, Inc. All other 3rd party hardware and software are trademarks of their respective owners.