RAID 1 question

[guitarguy84]

I curently have Windows XP and I want to upgrade to Vista, and also at the same time run a RAID 1 setup between my drives. I have one single 320gb drive in my pc and just today I bought a second one, which is yet to be installed. I want to backup all of my important files onto one of the drives if possible. My question is, would setting up the RAID 1 array format both drives?
I have never used RAID before so anyone who has can help out alot

 

[Siggy19]

RAID 1 means disk mirroring. In other words, everything written to one disk is written to the other at the same time. They are treated like a single disk. Not only would it be pointless to backup one onto the other, it is not possible without unRAIDing the disks.

The benefit of RAID 1 is that one disk failing will not lose you any data. However, it is also possible for the house to burn down or the computer to be stolen, so it is sensible to have some sort of off-site backup available. This can be done using one of the online backup services which will automatically back the data up to the net whenever your PC is running.

RAID 1 is slightly faster than a single disk to read the data, but can be a little slower writing it (since it must be written in two places). RAID 1 also only provides half of the disk space of the two drives since there are two copies of everything.

The most common alternative to RAID 1 is RAID 0, which is also called 'striping'. This effectively spreads the data across both disks and so is usually noticeably faster than a single disk (the data can be in two places and so is not slowed down as much by the speed of each disk). It also provides the full capacity of the two disks. However, if either disk fails, all of the data can be lost.

 

[ShadowFlash]

Some controllers do allow you to preserve the data from the original drive, and add the second as a mirror. This usually can either be done in the controller BIOS, or even with the software RAID manager used with your particular controller. Not all controllers support this however.

The one place where you'de see performance in RAID 1 is from multiple simultaneous reads, as each drive moves independently on reads. This will not give you more sustained throughput like RAID 0 does though. The first random access time would be equivalant if not slightly slower than a single drive, but subsequent random access times between the next write cycle does have the potential to improve due to positioning of the heads i.e. one head is substantially closer from the previous read than the other one. The gain in performance is dependant on the quality of the controller used. This is also the reason why random writes can get worse, as the heads now have to re-synchronize. You will see some improvements over a single drive set-up in performance, but nowhere near the same as with RAID 0. The downside of course, is the risk of losing all your data to a failed array. There is no way to re-build a RAID 0. This can occur for many reasons other than hardware failure. Make backups often and run on a good UPS for RAID 0. I'm not saying the performance gains aren't huge, I run them myself from time to time, just make sure you know what you're getting into.

 

[guitarguy84]

NOTE: I already know the difference between RAID 1 and 0....
Let me reword this in different terms.
Is it possible to: backup my data from my current hard drive (Hard Drive 1) onto my newly purchased
hard drive (hard drive 2) then install vista on HD 1, and before I setup RAID, get all my backup files from HD 2 onto HD 1, then format HD 2, then setup RAID 1?

 

[jitpublisher]

If the controller supports building the mirror from an already established disk, most will not do this.
On the lighter side, and not trying to be offensive or anything, RAID 1 is pointless unless this system is a server that must run 24/7.

 

[ShadowFlash]

Well I never consider RAID 1 pointless, but typically I build workstations that need to be operational "no matter what" during work hours. I do agree, that for most home set-ups, RAID 1 can be a waste, because it's no replacement for backups. Read the FAQ for advantages and disadvantages...
http://www.tomshardware.com/forum/43125-32-raid

With that being said, as I have mentioned before your controller card may support the ability to clone the drive into a RAID 1 set without destroying the data. We would need to know the type of controller to know for sure. Or you could read the motherboard manual if its on-board.

Assuming it does support this, your migration steps would be as follows....

1: Clone your existing drive into the new RAID 1 set.

2: Using re-partitioning software if needed, create a 2nd storage partition on the RAID set and move all of your files to be saved onto that partition.

3: Now you can Re-boot with your Vista Set-up Disk and Install a new OS on C: safely. You can re-format the partition safely because all of your files now reside on D: Just make sure you don't re-format D: in set-up.

4: Voila'...You now have a RAID 1 set with a new OS without losing any data.

You only have to do these steps if you are choosing to install a new OS. If you are not, then clone the drive in the controller card BIOS and you're done.

If your controller does not support this feature, then you are pretty muched fooched, and need to make backups and start from scratch. You probablly should make backups anyhow, in case something goes wrong

An alternative 2 drives non-raid as follows....
Drive 1: C: windows/System + swap file ( 40GB ) /// E: Storage Files ( 100GB ) /// G: Image of D ( 80GB )
Drive 2: D: Large Programs + swap file ( 80GB ) /// F: Image of E ( 100GB ) /// H: Image of C: ( 40GB )

If Drive 1 fails then your OS and storage image can be re-loaded from Drive 2

If Drive 2 fails then your files are still backed up on Drive 1

This Layout of splitting your Programs and OS on different spindles will probablly yield more performance than a RAID 1 without the Risk of RAID 0. Typically you would install whatever Programs that access your storage files on D: and only the OS, System tools, and A/V on C: Partition size can be changed to reflect your usage patterns. The only sacrafice you make is the added time of restoring your images if a drive fails. With intelligent planning, using multiple partitions and multiple individual spindles ( or even RAID sets ), can improve performance and reliability when a small number of drives are involved.