Does a software raid break when reinstalling the OS?

windows software-raid

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Solution 1

Software RAID is RAID handled by drivers in the OS. By definition, when you're installing a new OS onto disks configured with software RAID the new OS is going to see the disks as "disks", rather than as a RAID volume. (A hardware RAID controller abstracts the disks in the RAID volume away and shows the OS a generic "disk".)

If you're installing the same OS, it should "detect" the existing software RAID configuration and use it. That will vary from OS to OS.

Edit:

Finding official Microsoft documentation on this is proving needlessly difficult. From what I'm finding, Windows 7 Professional, Enterprise, and Ultimate support software RAID 0 and RAID 1. My experience with prior versions of Windows client OSs was that no software RAID was permitted.

Solution 2

In Linux there is a special partion type for software RAID. At first you create partitions on each HDD, then assemble them into array. In begining of each partition persistent superblock is written, so kernel could recognise existing RAIDs.

In my practice restoring RAID after OS reinstall was quite easy. Basically OS will automaticly find existed RAID and restore it. That is correct if HDDs were not reconnected in different order in SATA, SAS, SCSI ports and their device names got changed. In that case you will need to assemble them manually.

Solution 3

The answer is of course "it depends" :-)

The new OS needs to detect that the old OS used RAID and in which configuration or it can't access the data.

Most OS will do that in most cases, It worked for me with installations of Linux, OSX and Solaris, all of it RAID1 mirroring. I don't have any experience with Windows.

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Svish

Software Developer, Geek, HSP, SDA, ..., open, honest, careful, perfectionist, ... Currently into indoor rowing and rock climbing, just to mention something non-computer-related... Not the best at bragging about myself... so... not sure what more to write... 🤔

Updated on September 17, 2022

Comments

Svish almost 2 years

Does software raid break when reinstalling the OS? If yes, is there any way to prevent it, or recreate it without data loss after the reinstall? If no, is there anything you have to remember when doing it so it doesn't? Or is it just fixed automagically?

The particular OS I am wondering about is Windows 7 and Vista, but more general answers are more than welcome.
- fretje about 15 years
  
  I didn't know software raids had brakes (en.wikipedia.org/wiki/Brakes ;-)
- squillman about 15 years
  
  Fixed the title, in case anyone's wondering where fretje's comment's coming from
- fretje about 15 years
  
  There's still a 'brake' in the body...
- Svish about 15 years
  
  oops, sorry, haha. at least I was consistent :p will fix it.
Brettski about 15 years

"Should" that was my thought too Evan. :)
Svish about 15 years

So windows only supports striping? No mirroring? Guess I will have to stick with the raid controller on my motherboard then...
ThatGraemeGuy about 15 years

The client versions of Windows only support striping and spanning. Server versions also support RAID1 and RAID5.
Oskar Duveborn over 14 years

What? No no, Windows clients support striping, spanning and mirroring - with mirroring any data disks being quite useful on a standalone workstation ^^ (not replacement for backup of course)
Spence over 14 years

@Oskar: Windows 7 Professional supports striping, spanning, and mirroring. That support wasn't in XP Professional, AFAIK. I don't know about Vista-- I've managed to almost totally avoid it.
Nate almost 14 years

XP and Vista only support striping and spanning.