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PowerVault 725N RAID: How can I mirror my C: partition from Disk 0 to Disk 1?
How can get it to mirror the current information from the first partition of drive 0, the C: system drive, to the first partition of drive 1?
I got an emergency call in from someone with a Dell PowerVault 725N, which I know nothing about. From what I read, it was set up as a typically as a two RAID-1s, one for OS C:, one for factory OS D:, and a big RAID-5 across all 4 disks E:. It lost a disk. However, when it lost a disk, the RAID-5 no longer worked with the one drive bad. Obviously that shouldn't have happened, but it did. I gathered that the drive was hanging the bus sometimes because sometimes the OS wouldn't freeze also. The fix was to remove the bad drive, which I did, and copy off the data, much to their relief. The found a new drive in town for it, and I put it in. This is where the problems started.
- When I put in the new drive, it came up fine, I wrote the signature to the disk, and set it up dynamic.
- The RAID-5 E: replicated to the disk fine, but not the mirror of the C: I could not get it to mirror, so I broke the mirror, and deleted the "missing disk" It only holds 4 disks, and all 4 are there.
- When I try to mirror C: to the free space on the new drive, it returns the error: "Could not allocate contiguous space or partition." before I can even select the modify button.
- I deleted the E: volume, RAID-5 volume, to get all of the space back on the new drive. Therefore, I have a drive 0, with the OS on it in the first partition, a drive 1 with nothing on, and set up dynamic, and drive D: which is mirrored to the first partition of disk 2 & 3.
- Again, when I highlight drive C:, and select Add Mirror, I still get the error: "Could not allocate contiguous space or partition." Obviously there is a massive amount of space on drive 1 to mirror to.
- Dell pulled all of the docs that people were using to fix this problem. How can get it to mirror the current information from the first partition of drive 0, the C: system drive, to the first partition of drive 1?
Thanks!
JToering
113 Posts
1
June 14th, 2013 15:00
After many reboots, reading manuals and posts, trying many methods with no avail, I finally figured out the problem. As it turned out, I had no chance of getting it to work the way it was. The fix, and the ONLY thing that made the difference, bar none, was updating the BIOS to the latest, 08. After that EVERYTHING worked EXACTLY as advertised.
JToering
113 Posts
0
June 14th, 2013 06:00
Theoretically, another way to add a mirror is to use the PowerVault NAS manager, click disks > volumes, highlight the disk, and select reconfigure from the task list. However, the only item that displays in the task list is properties, so that doesn't work either.
JToering
113 Posts
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June 14th, 2013 13:00
- I did a test volume by creating a new one, and then added a mirror. Everything worked fine. That means the error that was returned when I tried to create a mirror for the C:, "Could not allocate contiguous space or partition.", is entirely bogus, a bug in Dell's software. My current theory is that for some reason, it is unable to mirror the system drive when active. If true, that means the hot swap functionality doesn't actually work for drive 0 or drive 1, because those two contain the operating system and its mirror. Only the RAID-5 portion can be restored to optimal, thereby leaving the operating system vulnerable to a disk 0 failure in the future, since it no longer would have it's mirror after the loss and replacement of disk 1. There is no RAID BIOS, since the 725N is a software raid. I do have some CDs from the customer, but there is no CD/ROM drive. My next step is to see if there is anything on the disks I can use, and if so, buy a USB CD ROM drive, since the 725N doesn't have one.
sheepskins
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June 20th, 2013 08:00
How to replace id2
Shut down system.
Remove disk 2
Install replacement disk in slot 2
Boot to the o/s and go to array manager console
Right click on disk 3 d drive and remove mirror (try both sides if necessary)
Right click on disk 3 D drive and add mirror
Wait 5 minutes to allow rebuild to complete.
Note: You must rebuild the mirror first !!!
Right click on disk 0 E drive and repair raid 5 volume.
After the rebuild completes 4-10 hours later…..
Right click on the missing disk which is now just a shell and delete.