RAID 1 question (1 Viewer)

[Eric_L]

I have a PC which I will be using to store my HD digital family films. Due to the size I want to have a dedicated drive for them. I also would like to have RAID 1 set so that if I have a drive fault it will not be the end of the world.

I had thought about using an external drive like Western Digital My Book Pro II, but I thought maybe it owuld be cheaper and faster to use internal hard drives.

What I don't know is if I can have one drive, the one the OS is on as a regular drive and the other two in a RAID 1 configuration. Is that possible or do I have to include all drives in the computer in a RAID array?

In other word;

Drive C: OS resident. One drive. 300 gig drive

Drive D: RAID 1 - two disk array. 2 X 1 ter drives - 1 ter total storage

I've not set up a RAID system before - so this is a new adventure for me. I am hopeful someone here with some experience coud guide me.

Thanks

 

[Ken Chan]

It is possible, depending on motherboard, or whatever you're using for RAID. For example, if you're using all SATA, and you have four ports, and you can RAID 3 and 4 without having to do anything with 1 and 2, then it's pretty straightforward. Just put the OS on SATA 1. The boot drive has to come "before" the others.

My experience with RAID 1 was not good. This was when Vista first came out, and it was probably the drivers, but in a RAID configuration, the drives would not flush the write cache before restarting. In other words, the drives got corrupted after doing a Windows Update. At least they were corrupted identically Also, the array seemed pretty brittle, and had to rebuild itself for no apparent reason. The drivers have been updated since of course, but I haven't bothered to try it again.

RAID 1 is really more suited for maintaining uptime even in the event of drive failure, like if you're running a server or a business. For consumers, a better choice would be aged backups onto disks that are kept off-site, in case of crime or calamity. You could use external drives and rotate them through a safety deposit box at the bank, or some secure location at work.

For example, RAID 1 will not save you if you accidentally delete a file -- it's immediately gone from both drives. Deleting a single file is often recoverable, but there are ways in which you can be making some changes and get yourself in trouble. If you have backups from yesterday, or backups from last week or last month, you're "safe" or rather, "safer".

You could do both RAID and backups. Check out Windows Home Server as a backup solution.

 

[Eric_L]

Thanks Ken.
You're right. I've decided against RAID 1 and instead will do a backup drive. I will have them on UPS for power issues. I'm not so paranoid about theft or disaster, but maybe someday I'll get a second backup and mirror the backup one in a while and keep it at my office.

My folks hard drive got corrupted and they lost some sentimental files. I have it stowed away somewhere. One day I hope to try to recover them, but I am not optimistic...

 

[Kimmo Jaskari]

RAID is in fact a great solution for ensuring against the failure of any single drive, but it's only one step in a data protection scheme; like many things it's not sufficient in itself to ensure you're safe.

Backups, preferably backups taken off site so if your house burns down you still have the data, is one such part of data safety. This could be either through an online service (like the free Dropbox.com for instance, which has been a great addition to my desktop computing experience) or by regularly dumping data to an external drive and moving it manually to a friends or relatives house... whatever works.

As for brittle RAID... on my desktop machine with the nForce chipset I've been running RAID0 for two years straight and had zero RAID-related problems. Of course, that is an intentionally brittle setup, if one drive dies all the data is gone - I use it simply because it speeds up data access considerably as the drives share the load in RAID0. I would assume a RAID1 setup on it would be equally unobtrusive and trustworthy (no reason for it not to be.)

However, with plain RAID1 you are still not secure from accidental deletion; that is where things like snapshots on the OS level comes into play. On Macs they call that Time Machine, for instance, and Windows has its VSS.

Once you put all those things together, you have quite decent security for your files. I personally have a server on which I run OpenSolaris; OpenSolaris has the superb ZFS file system that keeps checksums of all the data on it to avoid silent data corruption, allows for very quick and easy snapshots to safeguard against accidental deletions and more.

However, the combination of RAID1 or 5, regular backups and some sort of snapshotting functionality means you'd have to try very hard to actually manage to lose data.

 

[Al.Anderson]

I second everything Kimmo said. I'll add that I've been running the same RAID0 hardware for 5 years with no problems at all. I do backups to other disks and find that my biggest headach is managing the backups. (If I destroy BU n-2 when I make BU n-1, what if I find out I accidentally deleted something in n-1? So, I keep too many backups around. Oh, delta backups make me queasy; what if the baseline is corrupted?)