Raid Conversion

[lopix]

Here's a bit of a weird one. Is it possible to setup 2 drives in a raid0 array, then add another 2 drives, configured as another raid0 array, then mirror the first array onto the second to create a 0+1 config?

 

For added difficulty, can the first array be setup and have data written to it, then the second array added a month later, with the mirroring added, without losing the data on the first array?

 

For the slam dunk, can this be done with an onboard raid controller, such as Promise or Highpoint?

 

Anyone?

[plizzo]

Is it possible to setup 2 drives in a raid0 array, then add another 2 drives, configured as another raid0 array, then mirror the first array onto the second to create a 0+1 config?

yes it is, and it is called raid 0+1

 

For added difficulty, can the first array be setup and have data written to it, then the second array added a month later, with the mirroring added, without losing the data on the first array?

not likely, ususally when you build an array all drives start with a fresh format so you would have to start from chance(im not 100% positive on this one however)

 

For the slam dunk, can this be done with an onboard raid controller, such as Promise or Highpoint?

not unless they have started putting better onboard raid controllers as of late. as far as i know all onboard controllers only support raid 0 or raid 1. you will have to buy a card to setup raid 0+1.

 

if you need any more info check out this site, it explains all the different raid possibilities.

[lopix]

Actually, I figured out a way to do it. I am going to be using the Abit IT7 Max 2 rev2, which has the Highpoint controller which allows for 0+1. What I have to do is create the 0 array, use it until I get the 2 other drives, then backup the data and destroy the 0 array and create the 0+1. Dump the data back and I am good to go. Not elegant, but it will work.

[Calyco]

That's probably the only way to do so. Just backing it up and throughing it on again. Sometimes the tough way is the only way.

[DNAT]

lopix, in short: NO, YES, SORT OF

 

The Highpoint HPT370, 372 on many mobos and the HPT374 card controller will all do Raid 0+1. I just checked my HPT372 manual and the only way to NOT DESTROY data on a drive is to use the "Creat Duplicate [make mirror, leave original]" option.

 

This is the YES, above. This option uses an EXISTING RAID 0 array previously created, and mirrors it onto a newly created 2nd array, thus "duplicating" or making the mirror. You now have a mirror (1) of your original striped set (0)...hence RAID 0+1 (sometimes written as RAID 10 [one-zero, not ten]) Note, this option (mirror (1) of a stripe set (0)) will DESTROY everything on the newer 2nd array drives used for the mirror.

 

The HPT370 and 372 controllers have max 4 drives, 2 make a stripe set (RAID 0) and the other 2 could be used for the mirror (RAID 1). You could also use 3 or 4 drives just for RAID 0 (but you now have NO data protection from a mirror). It is very fast though, I played with a 4 disk RAID 0 before a calmed down and made my RAID 0+1 array.

 

I believe the HPT 374 controller can actually run 8 drives

 

 

Cheers,

DT

[lopix]

Excellent, thank you. It is going to be the HPT374 controller, so I should be okay. I am amazed that it is possible to create the 0/1 from an existing 0 array. But it does make sense, to be able to, since the original array will only be mirrored onto a new array, made with 2 fresh and empty drives. But, I may just wait the little longer and go with all four drives to start. I have also heard that there is a pirate BIOS for my mobo that allows the HPT374 to run a raid 5 array - now that would be cool!

[lopix]

Excellent, thank you. It is going to be the HPT374 controller, so I should be okay. I am amazed that it is possible to create the 0/1 from an existing 0 array. But it does make sense, to be able to, since the original array will only be mirrored onto a new array, made with 2 fresh and empty drives. But, I may just wait the little longer and go with all four drives to start. I have also heard that there is a pirate BIOS for my mobo that allows the HPT374 to run a raid 5 array - now that would be cool!