# AMD RAID volume not showing up (corrupted GPT) [SOLVED]

## smadasam

I have a AMD MB based RAID 5 array on my machine.  It shows up as /dev/sdc, but inspecting the drive with parted, it looks like it is only seeing the first disk or only 2TB.  It should be about 4TB.  

It would seem like the kenrel is using the wrong driver for the controler.  Do you know how to get the correct one on so I can mount my partition?

----------

## Jaglover

Not sure what RAID you have there but it sounds like fakeraid.

You may want to read this http://skrypuch.com/raid/

----------

## smadasam

It is the AMD RAID controller on the SB950 south bridge on my mother board.  It is a fake RAID if you mean that it doesn't actually have a dedicated XOR processor and used the driver (software) and CPU.

I am not sure how your post is helping me get the data off of my array.

----------

## Jaglover

Nothing in your initial post implied you need help getting data off your array. Sorry for replying.

----------

## smadasam

No biggie.  I guess I only said I wanted to be able to mount partition and not necessarily get data off of it..

In any case, it seems like I am out of luck.  I don't think dmraid supports AMD (based of promise) RAID 5 sets.  I will have to try my luck with Windows where there are actually drivers for AMD RAID 5.

http://ubuntuforums.org/showthread.php?t=1577338

----------

## smadasam

1. If you have an AMD motherboard and try to use the onboard controller for RAID 5, it isn't supported with dmraid, so I don't think you can use it in Linux.

2. Using gdisk, I was able to repair my disk in Windows.

So my GPT was damaged:

```
C:\bin>gdisk 1:

GPT fdisk (gdisk) version 0.8.5

Caution: invalid main GPT header, but valid backup; regenerating main header

from backup!

Caution! After loading partitions, the CRC doesn't check out!

Warning! Main partition table CRC mismatch! Loaded backup partition table

instead of main partition table!

Warning! One or more CRCs don't match. You should repair the disk!

Partition table scan:

  MBR: not present

  BSD: not present

  APM: not present

  GPT: damaged

Found invalid MBR and corrupt GPT. What do you want to do? (Using the

GPT MAY permit recovery of GPT data.)

 1 - Use current GPT

 2 - Create blank GPT

Your answer: 1
```

Then I used the v option (verify disk) to have gdisk tell me how to fix it:

```
Command (? for help): v

Problem: The CRC for the main partition table is invalid. This table may be

corrupt. Consider loading the backup partition table ('c' on the recovery &

transformation menu). This report may be a false alarm if you've already

corrected other problems.

Caution: Partition 1 doesn't begin on a 8-sector boundary. This may

result in degraded performance on some modern (2009 and later) hard disks.

Consult http://www.ibm.com/developerworks/linux/library/l-4kb-sector-disks/

for information on disk alignment.

Identified 1 problems!
```

Then followed the rest of the instructions:

```
Command (? for help): r

Recovery/transformation command (? for help): ?

b       use backup GPT header (rebuilding main)

c       load backup partition table from disk (rebuilding main)

d       use main GPT header (rebuilding backup)

e       load main partition table from disk (rebuilding backup)

f       load MBR and build fresh GPT from it

g       convert GPT into MBR and exit

h       make hybrid MBR

i       show detailed information on a partition

l       load partition data from a backup file

m       return to main menu

o       print protective MBR data

p       print the partition table

q       quit without saving changes

t       transform BSD disklabel partition

v       verify disk

w       write table to disk and exit

x       extra functionality (experts only)

?       print this menu

Recovery/transformation command (? for help): c

Warning! This will probably do weird things if you've converted an MBR to

GPT form and haven't yet saved the GPT! Proceed? (Y/N): y

Recovery/transformation command (? for help): w

Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING

PARTITIONS!!

Do you want to proceed? (Y/N): y

OK; writing new GUID partition table (GPT) to \\.\physicaldrive1.

Disk synchronization succeeded! The computer should now use the new

partition table.

The operation has completed successfully.
```

Thank you gdisk guys!  You saved my bacon.

----------

