Deleting Raid 1 array

butlerbd · 02-20-2012, 11:41 AM

I have an older ASUS motherboard (P4s8x) with a promise FastTrak 376 raid utility in the BIOS. My OS is Windows xp. I have a Raid 1 array set up on two 80GB hard drives. My Question is: If I use the delete command and delete the array will my data on the hard drives remain intact? Will I be able to reboot and use both hard drives again? The MB documentation says deleting an array does not! delete any data from the hard drives. I want to be sure before I delete the array. Does anyone have any experience with this issue?? I appreciate any help.

burnleylad_84 · 02-20-2012, 02:13 PM

Effectively raid1 is mirrored mode so data on one drive will be mirrored on the other so removing one drive or erasing raid1 should keep that data intact.

If it was raid0 then you would have problems.

butlerbd · 02-22-2012, 09:19 AM

burnleylad_84, Thanks for your response. I thought that the Raid1 mirrored array might keep at least one drive intact. I have backed up my data and will delete array. Will post the outcome. Thanks again.

bobkat2 · 06-28-2012, 10:04 AM

FWIW, for those with AMD RAID BIOS, a RAID 1 array can be safely Deleted (option 3) without loss of data. It's scary to hit the Delete key after the warning that 'all data may be deleted', but for RAID 1 the instantaneous response is simply to the effect that 'no array is found' while there was no time to delete data from either drive or mark any partitions as unusable. Everything remains intact. This would NOT be the case with other RAID levels which involve Striping.

I'm running RAID 1 using 2@500GB drives on a Gigabyte mobo with AMD RAID in the BIOS. On two occasions, with different drives, one of the drive pair has failed and I have needed to Delete the Array. The first time, I forgot to keep detailed notes. The second time I found this thread while searching to fill in the gaps in my memory. In both cases I did a full system backup or clone to another larger drive from the crippled "Critical" array as a precaution, though I really hoped I wouldn't need it. Then I Deleted the Array with no loss of data and no need to restore from the backup. In the first case I was able to use AMD's RAIDXpert to rebuild the array, complete with OS. In the second, today's case I will not rebuild this array containing my OS since it is a good time to modify my backup strategy to do hourlies to a second internal drive with dailies to a RAID-protected NAS.

Tyree · 06-28-2012, 12:09 PM

RAID is commonly more trouble than it's worth.
You can easily back up data by making images or storing the data on another partition or Hdd.

**LMiller7** · 06-28-2012, 04:14 PM

RAID 1 is of considerable value when used for it's intended purpose. That purpose being to allow continuous access to your data even in the event of a drive failure. Drive replacement can be deferred to a more convenient time. On a busy network this is of considerable value where taking a server down can be very disruptive to network usage. This is not normally a serious problem on a desktop and the cost of RAID 1 is often difficult to justify.

Unfortunately, many home users see RAID 1 as a form of automatic backup. This is dangerous because it offers protection only from drive failure and none for other causes of data loss. No form of RAID is a replacement for maintaining backups.

bobkat2 · 07-02-2012, 11:05 AM

Quote:

Originally Posted by LMiller7

RAID 1 is of considerable value ... to allow continuous access to your data even in the event of a drive failure. Drive replacement can be deferred to a more convenient time. On a busy network this is of considerable value where taking a server down can be very disruptive to network usage. This is not normally a serious problem on a desktop and the cost of RAID 1 is often difficult to justify.

Unfortunately, many home users see RAID 1 as a form of automatic backup. This is dangerous because it offers protection only from drive failure and none for other causes of data loss. No form of RAID is a replacement for maintaining backups.

I've been running RAID 1 for a few years on my primary desktop to maintain 'continuous access in case of a drive failure' and to 'postpone replacement to a more convenient time'. I have matching drives in other systems on my SOHO network so that in theory a spare is always available. However, in practice, the spares always get used for something which needs to be migrated before they truly become spare. My experience has been that there is never a convenient time for a replacement.

With RAID 1 on my desktop I was doing weekly incremental backups with monthly full backups to a RAID-protected NAS. My present thought is that RAID 1 (or any other level) is not a good match for an OS-drive in a PC where the drive count is minimized to reduce system power. That is why I will be trying hourlies to a second internal drive with dailies to the RAID-protected NAS.

In a previous life as an employee of a major computer manufacturer I designed RAID hardware-firmware-software for Enterprise Systems. Migrating that knowledge into a SOHO system is an ongoing learning experience.