Backup an image of a boot drive to a RAID 1 & perform restoration?
March 19, 2013 2:17 AM   Subscribe

I have a PCI-E SSD as my boot drive, and a win7-created RAID 1 on two 3TB drives. My boot drive has my user folder on it, but my documents, music, pictures, videos, etc folders shortcut to their respectable folders on the RAID. I would like this to be a full redundancy scheme and it is, but I've run into several nags and I would like to know how to fix them and prepare a fix-it plan before any of the drives fails.

The PCI-E SSD is OCZ RevoDrive 3 X2 240GB.

First the nags:
The backup is more than 240GB. I am thinking that Windows is including not only multiple versions of files but also backing up the target's shortcuts as well. This is stupid considering that the RAID 1 has already taken care of those folders. How do I make automatic periodic image backups of the boot drive only and without versions of the files? (I would still like restore points for the boot drive--but that still fits in the 240GB, right?)

Preparing for the worse:

-If my PCI-E SSD fails, I will have to temporarily resort to a mechanical drive until I replace the SSD. How do I quickly restore the boot image (stored on the RAID 1) to this mechanical drive? Lastly, once I've obtained the replacement PCI-E SSD, how do I restore the most recent boot image to that? I've heard it's super difficult. Any surefire methods and instructions?

-If one of my RAID 1 drives fail, how can I locate the bad drive, replace it and restore the mirror without putting the good drive in risk?

I am willing to spend money on software, but only if its “set it and forget it” and offers flawless restoration. Also, I because of limited case space, I rather avoid setting aside another drive or a separate partition for a perfect image copy of the boot drive.

Honestly, I feel that once these questions are answered, this HD setup is a very redundant and cheap way of keeping a hold on my life's data work and a functional computer. If anyone can offer answers to any of the questions here I will greatly appreciate it and I will give back to the community by spreading this method.

One example of this would be building computers for family and friends. I've heard too many stories of people's drives going bust, so this would make the computer I build for them very reliable. The only problem is I need to provide instructions in case something does go wrong.

Lastly, I question if there is a method to move a software raid to a hardware raid if in the future I happen to upgrade to a better motherboard that supports multiple raids (since the pci-e ssd is technically a raid as well). How would I do this?

Bonus question: Let’s say I was to install a “Hackintosh” on a separate SSD/HD. What would be the way to make the RAID visible and editable by Mac OS X? How would I do a boot drive image backup onto the RAID as well?

Many thanks.
posted by ihavearedcouch to Computers & Internet (6 answers total)
 
Okay, since it's been awhile since you asked, I guess I'm going to take a shot at this first - I can't provide exact answers but I hope to at least push you in the right direction.

If my PCI-E SSD fails, I will have to temporarily resort to a mechanical drive until I replace the SSD. How do I quickly restore the boot image (stored on the RAID 1) to this mechanical drive?

The Windows partition on your SSD is probably acting as a RAID controller, so if that SSD or Windows partition were to fail, you probably wouldn't have immediate access to your storage backup. Want to test whether you can get to them? Simulate a failure - yank the SSD from your computer and boot from a CD copy of Ubuntu and see if you can access your data (be sure not to write anything to those drives). I haven't done this testing myself, but I bet you will not be able to access this data. There's a possibility that you could create a second Win7 boot partition and it will know how to properly read your RAID, and I'd test this theory if I had your setup (install/copy Win7 to an old disk you have lying around and try to boot from it instead of the SSD).

If one of my RAID 1 drives fail, how can I locate the bad drive, replace it and restore the mirror without putting the good drive in risk?

If one of your RAID drives fail, the other is at risk immediately - that's the inherent problem with RAID1. Again, back up your data (and be able to restore it - remember, redundancy is not the same as a backup), and test: pull one of your physical RAID drives while the machine is running. See how the system identifies the problem and you will be in a better position to respond if it were an actual failure. I know this sounds somewhat cavalier and foolhardy, but I personally learn best from "oh shit!" moments.

Lastly, I question if there is a method to move a software raid to a hardware raid if in the future I happen to upgrade to a better motherboard that supports multiple raids (since the pci-e ssd is technically a raid as well). How would I do this?

No. Move the data to the hardware RAID manually or there will be tears.

To be honest, I think there are several problems with your approach to the problem, and I think these could be corrected with more experience. If you're truly want redundancy on the cheap, RAID1 both your boot partition and storage partition, then test these configs by pulling a drive and see how the system reacts, then replace with a different drive and wait for the system to rebuild - hell, see what happens if you replace a drive with one of a similar size by another manufacturer. Also, is there a reason you're using a PCI-E SSD instead of a normal SATA? Maybe I'm just not hip to the times, but it seems like a bad idea (and I have no idea how you claim it's "technically a RAID" unless you have multiple drives).

(I hope someone else chimes in because I've left a lot of knowledge gaps in my answer)
posted by antonymous at 9:41 AM on March 19, 2013


I'm not going to comment on the details of this. Instead, I will note that you seem to be making the mistake of thinking of RAID1 is sufficient for backup. It is not.

A good backup scheme protects you from multiple data-loss scenarios, including disk failure, filesystem corruption, accidental deletion, "bit-rot" and disaster, like theft, flooding, or a house fire. RAID1 only protects you from failure of a disk. It is best treated as protection against unplanned downtime, which is generally not that important for personal desktop systems, particularly ones that don't have a good backup scheme in place, because when a drive fails, you should probably stop what you are doing and deal with the problem anyway.

My high-level advice is:

Break the RAID. Use one of the drives as a backup target for your data files. Use the other drive as the online, live storage of that data, and also as a target for a bootable clone of your SSD. I don't know what tool to recommend, but there must be disk imagine tools that can do it automatically.

For your data, use something that does automatic versioned incremental backups to local media (ie your second hard disk) AND can automatically perform encrypted backups to an offsite location or service. One product/service that fills the bill is CrashPlan, but there are others.

Also, as far as economical RAID goes, software RAID is generally preferable to "hardware" RAID. Cheap hardware RAID generally offers few, if any, advantages, with the big disadvantage that, in the event of a hardware failure, you have to get compatible hardware in order to regain acces to your data.

Finally, your proposed system isn't "very redundant." You have two copies of your data, which is more like the bare minimum for redundancy.
posted by Good Brain at 2:38 AM on March 20, 2013


Thanks so much for your input, however I feel like I need to clarify on some things.

The Windows partition on your SSD is probably acting as a RAID controller, so if that SSD or Windows partition were to fail, you probably wouldn't have immediate access to your storage backup.

I have done this before, and the data is still available. However windows recognizes that the drive is dynamic and is missing its RAID 1 sibling. Also, I have enough faith in the application "testdisk" to get through and see the data. After all, RAID 1 is un-diced.

Also, is there a reason you're using a PCI-E SSD instead of a normal SATA?

My computer doesn't have SATA III, and this PCI-E SSD beats it by over 3x the speed.

(and I have no idea how you claim it's "technically a RAID" unless you have multiple drives).

There are 4 sandforce controllers on the PCI-E SSD, each one controlling 60GBs, so when working together (as hardware raid) it makes 240GB and with blazing speed. Although in my eyes, its a very, very fragile card (has the memory chips exposed and all).

It is best treated as protection against unplanned downtime, which is generally not that important for personal desktop system

I will clarify since earlier I didn't want to bore about loose details. I make music, and I value in-the-moment creative flow. Once you lose it, you'll never get the same one again, (you might try but it simply isn't the same). That is why if I lost something from yesterday, a backup from the week before wouldn't do me any good. As for versions, I developed a habit of saving multiple versions as I go, for pretty much everything. Things I am certain: deletion and saving over the originals so they no longer exist; I do without any regrets and I never look back. If I felt bad I would simply retrace my steps personally and try to get it back, but then again this isn't the issue with creativity---I save it all. This is another reason why I have 3TBs dedicated to this.

More frequent backups would annoy me, as opposed to doubling up on the data read/writes in the moment. Now when I'm watching a movie, playing a game, downloading, the backups would have to occur, and will cause HD/internet slowdowns. Also, I like turning off my computer. Saves power and makes it easier for me to sleep.

To me a backup is just another copy. Fires, possibility of water damage, theft, etc should have protections of their own.

Is is possible to have an backup scheme that is instantaneous? so that it acts like a raid but isn't really one? Would be nice if it even hides the disk itself in windows?
posted by ihavearedcouch at 3:48 AM on March 20, 2013


I continue to encourage you to rethink your conception of "backup."

Backup need not be a week, or even a day out of date and it doesn't need to be annoying. Crashplan defaults to backing up new and changed files every 15 minutes, and can be set to an even shorter interval. For my, the impact on system performance of checking for changes frequently is minimal and imperceptible because it relies on the operating system itself to compile the list of new and changed files in the course of ordinary filesystem operation. The impact of actually backing up those changed files is also minimal and imperceptible because, in my case, the data is on an SSD, so there is plenty of IO ops capacity available for my use while the backup software checks for which portions of the file changed and then copies it off my main disk. The offsite backup is also imperceptible, I told the backup software to limit uploads to less than my uplink capacity, plus I use properly tuned QoS on my router to avoid high latency due to large, filled network buffers on my cable modem. Other software has similar capabilities.

Now that I know your use case, I better understand your attraction to RAID, and your concerns about automatic backup. If you need high availability so you don't break your flow in the relatively rare event of a disk failure, then RAID1 is the way to go, but you are already accepting some break in your flow in the event of a failure of your SSD.

If I were you, I'd have more confidence in carrying on in the face of a drive failure in my RAID if I knew I also had a good, recent backup of my data. Good automatic backup software can give that to you. If it does interfere perceptibly with your digital audio work, you might need to pause it, but it can still take care of things for you automatically when you aren't doing such sensitive work.
posted by Good Brain at 6:36 PM on March 20, 2013


I'm starting to see how this website is failing. Everyone is more "you should do it this way instead" instead of "this is how you do that which you're trying to do."
posted by ihavearedcouch at 1:43 AM on April 7, 2013


After months of research I've finally found the answer: DatOptic's iMirror525A.
Hardware raid with port multiplication... Amazing since I don't have any more pci slots to spare. DatOptic also has different models for more drives.
Cross platform use not a problem, for read/write software is available for mac/pc. Hardware raid means OS treats it like a single drive.
I will purchase this, and test out and write my experiences later.
posted by ihavearedcouch at 6:39 AM on July 14, 2013


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