I was looking for a backup solution for my Mac Mini and my G4 Powerbook. Initially I was looking for a dedicated machine to do backups but I didn’t have any old machines around to put a RAID setup in. I really don’t keep computers for that long, but this would have been a good use for it. Instead I looked into external hard drives that I could use to rsync data from my computers using cron. I searched Google for RAID enclosures and most of them uses RAID 0 stripping. I wasn’t looking for speed because I was using it as a backup unit so I searched some more for RAID 1 mirroring enclosures. Most of the time the drives were way too expensive or were so huge. It really wasn’t what I was looking for. I found one enclosure the OWC Mercury Elite enclosure that had the capability to perform RAID 1 with a firmware update. I ordered the unit for $130, and received it in a few days.

The nice thing about the OWC Mercury Elite enclosure is it matched with my Apple computers. I was looking more for function than aesthetics, but it’s always a plus if it doesn’t stick out like a sore thumb. I purchased two Seagate 300GB ST3300631A-RK drives to fill the enclosure. I was debating getting smaller drives, but I could always put the extra space to good use. I decided I could also backup some of my other web servers that I don’t host on site. Initially I used the standard cable select configuration on the drives hoping that the enclosure would detect it. The installation into the OWC Mercury Elite enclosure is pretty straightforward and fits in quite nicely. I find that it is hard to install drives in some computers is quite awkward and made for people with small fingers. I think manufacturers are a lot better at issues like this and take that into consideration when designing a product. To my surprise, the cable select didn’t work and I had to setup the drives in a Master-Slave configuration in order for Mac OS X to recognize it. I updated the OWC Mercury Elite enclosure with the firmware that supports RAID 1 and I was able to follow the directions on OWC’s website.

The RAID 1 configuration was a bit of a struggle. Setting the drives up as one large 300GB partition worked find using Apple Disk Utility. The drives would mirror and the RAID 1 setup worked. The only problem was I wanted 4 different partitions on my RAID 1 to use as boot drives on the Mac Mini and Powerbook in the event of a drive failure. I would be able to boot from the OWC Mercury Elite and rsync my data back onto the original drive and continue working with all must settings in place. Mac OS X Tiger did not support multiple partitions on the RAID 1 setup. I also tried creating different RAID 1 sets from existing partitions and this didn’t work either. I did a few searches in Google and people were having similar problems. I contacted OWC’s tech support and they were unable to help me. They said I should be able to do it but were unable to instruct me on how I should do it. I attempted to use diskutil from the command line to force the partition schemes into RAID 1 only to hit another wall. After searching some more I read that people were able to set my configuration up using Mac OS X Panther. I didn’t have a machine still running Panther, but I was able to boot from an old Panther install disk. I opened Disk Utility, but still had no luck trying to partition. After a couple of hours I decided that RAID 1 just wasn’t going to work for me.

I decided to go with plan B, which was to create the twice the number of partitions since I had twice as much space to use since the drives were not going to be in RAID 1. I would have one partition back up the machine using rsync every hour and the other partition would back up the machine nightly. This would allow me to have multiple snapshots of the drive at a given time. This seemed a little better since the RAID 1 setup would have been hourly and once that hour was up I was stuck with that image. After partitioning the drive and installing a fresh copy of Mac OS X Tiger I came across another problem. The OWC Mercury Elite enclosure would not allow Mac OS X to boot from the Slave drive. It showed up in Startup Disk, but when I went to boot it, it would always boot from the internal drive. When I installed Mac OS X Tiger on the Master partition it would boot only from holding the option key at startup. I figured this would work for me and it was better than not being able to boot at all.

In the end, my backup solution seems like it is going to work. I would have two backups for every machine at different time intervals. I would be able to boot from the hourly partition, which also seemed reasonable. The price seemed reasonable for what the drive was intended for and I was able to pick my own Seagate drives to fill it with. If you want to run RAID 0 or RAID 1 on a single partitions the OWC Mercury Elite enclosure will work for you. If you want to run multiple partitions or be able to boot from every partition this drive might not be the best solution. Hopefully with a firmware upgrade some of these issues can be fixed. If you have any experiences with this drive feel free to post any comments.