I do feel for you. I've lost data twice before, not having backups in place. Some of it was very personal, important to me, and irreplaceable.
1) The first time I lost data, I had no back ups. That taught me to back up important data.
2) The second time I lost data, I had actually been backing it up. So I went to the backups only to find that not a damn one of them worked, so nothing could actually be recovered. So that taught me that I'm not really backing up unless I occasionally test the recovery process to verify it works.
We've all seen many stories about #1, but I've also seen a few about #2. TEST YOUR BACKUPS.
P.S. From my own experience as well as years of reading forums, I feel RAID is a bag of hurt. Yes there are some pros, but they come with a lot of cons as well, some of which are unacceptable to me.
Most of the issues like this seen with hardware RAID tend to originate with the user, but this particular instance is definitely user. RAID is complicated, and can be disastrous for those that don't know what they're doing.
This even goes back to your second point. New users to hardware RAID tend to get it up and running, but never test out how the gear will react under failure conditions, nor test out any backup strategies that have been implemented.
Such mistakes are costly in terms of data loss, and time (not to mention the extreme stress involved).
Another thing to keep in mind is OS upgrades frequently kill disks that were on the verge. An OS upgrade is stressful. The boot disk is writing TONS of data, moving blocks, Spotlight indexes are being rebuilt, etc etc.
True.
This is no different than trying to use a degraded set that's in the process of rebuilding itself (start the rebuild, try to use the system, and another disk/s fails = array is gone, taking all data stored on it as well).
And for such situations, no backup = totally screwed.
I crashed a SAN at work with Lion beta 1. That was the end of my "Hey this is super OK and stable" foolery. I feel your pain but no backups and beta software is pebkac of the highest order.
Telling people on a forum full of geeks takes some balls though.
Yikes!
I hope that was only a test-bed system, and not the primary and any fail-over systems.
So he recovers his data - great! But what should a back up plan be for a large 18TB raid or More?
Smaller 3TB HDD's with sections of the data?
The cheapest way (cost/GB), would be use an eSATA card + PM enclosures and Green drives (use a software JBOD implementation <concatenation = single volume of all members in the set>, which OS X can do).
But there's other ways to get it done as well, such as an identical configuration, and use backup software to copy the data from one array to the other (do not use RAID 1, as problems will be duplicated; think user error, such as an accidentally deleted file).
*** This is a Serious Bugs Warning for RAID-5 Volumes using Lion's default RAID driver***
...<snip>...
What?
This doesn't sound right, as Apple's past RAID drivers were not written for Areca or any other 3rd party RAID card, but solely for their own Apple RAID Pro (LSI is the ODM).
Please understand, that drivers are specific to their makers' cards (i.e. you wouldn't want to attempt to use LSI's drivers with anything other than an LSI card, as things like what you ran into tend to happen).
In such testing, here's what to do (or for a new version of OS X installation):
- Make sure your backup is fully up to date.
- Shut down the system.
- Remove the RAID card.
- Restart and install the new version of OS X.
- When it's finished, install the Areca Drivers (assuming there aren't new drivers, then you'll have to experiment with the latest from the previous OS version).
- Shutdown the system.
- Re-install the card.
- Reboot.
In the case of Beta software, there is a very high risk that things will go wrong, even if the above procedures are followed (with a recent issue of a new version as well, but presumably, the card's manufacturer has had enough time to release new drivers at the same time).
I know your issues already happened, but hopefully this can help you not to repeat this sort of mistake again.
And I'm glad you were able to get your data back
(you previously gave me the impression you couldn't backup your data from the degraded set).
