Reading the title makes it sound like something that should be easy. I should be able to just pull out the drives in the order they are presented in the hardware, mark them as 0 through whatever and be done with it. However it has been my experience that when determining the RAID configuration, there are several considerations that must addressed before an accurate RAID setup can be resolved.
First of all there are many systems that present the drives in the opposite order they are configured in the array. The assumption is normally that the drives are ordered left to right 0 through the end. However, I have worked on SNAP servers that the drive order is right to left. This makes recovery difficult and can add hours to the time.
Hot spares that are not hot spares can add to the headache of determining how a RAID is laid out. I receive at least one RAID a month where the hot spare was actually part of the array.
RAID type is a big consideration when trying to determine the configuration of the RAID. I have received RAIDs that the client has sworn was two RAID fives when in fact it was a single RAID five, or a single RAID 0.
Finally, there are RAIDs that have no rhyme or reason. This seems to happen with JBOD mostly using the LVM handler. I just had a RAID with six different LVM partitions, three were single stand alone drives, two were RAIDed as RAID zero, and one was RAIDed as a RAID five. The LVM config file which is found in the meta data area of the drive showed 339 different iterations of configuration over the years.
As I began to do recovery of RAIDs I would us a hex editor and display the drive images on my monitor all at once. By viewing certain aspects of the file system, and in some cases the data I could determine RAID type, stripe size, block order and block rotation. I still to a large degree do this by hand as I receive a lot of RAIDs that do not have the NTFS file system on them. However, if the NTFS file system is on the array then I can determine all of the above mentioned configuration nodes with a piece of software.
The NTFS file system although dynamic has certain attributes that are static. These static markers combined with other variables can be used to determine the configuration. I have taken all of these rules that I have applied over the years and put them in a piece of software aptly named RAID Drive Order for NTFS. The software is simple to use and easy to setup. Just follow the video provided and you will have your RAID setup in no time.
Purchase RAID Drive Order Detection for only $9.99
More RAID Resources
- RAID 5 Stale Drive Detection
- Using Bad Block Frequency To Detect Stale Drives
- Determining A Stale Drive In Most RAID’s
- Check RAID Consistency Before Rebuild
- Analyzing RAID Parity
- RAID Data Recovery
- RAID 5 Data Recovery
