Rebuilding FakeRAID RAID 5 with new disk, no partitions show up, invalid PMBR

Question

I have a RAID 5 array with 4 2TB disks on a HP Z800. One disk failed and was swapped out for a new one.

I went into BIOS Intel Storage Matrix Utility and set the Array to rebuild with the new disk. The utility says that this will complete in the OS.

After booting into Ubuntu dmraid -s showed the status as nosync. dmsetup status showed the sync ratio was increasing and eventually (after 9-10 hours) it finished syncing. dmraid -s showed status ok.

So, assuming all was well, I rebooted, Ubuntu couldn't mount the raid array as normal, presumably because the volume name had changed, the xxx in /dev/mapper/isw_xxx_Storage.

There were no partitions shown in /dev/mapper, just the volume /dev/mapper/isw_jbbicjigc_Storage

Trying to mount the volume failed (obviously) so I tried to use kpartx

$ sudo kpartx -a /dev/mapper/isw_jbbicjigc_Storage
    Warning: Disk has a valid GPT signature but invalid PMBR.
    Assuming this disk is *not* a GPT disk anymore.
    Use gpt kernel option to override.  Use GNU Parted to correct disk.

From here I really have no idea where to go. I'd rather not reformat everything and lose my data but can if that is the only option.

Here is the output from a few relevant commands:

$ sudo dmraid -s
*** Group superset isw_jbbicjigc
--> Active Subset
name   : isw_jbbicjigc_Storage
size   : 11721073920
stride : 128
type   : raid5_la
status : ok
subsets: 0
devs   : 4
spares : 0

$ sudo dmsetup status
isw_jbbicjigc_Storage: 0 11721073920 raid raid5_la 4 AAAA 3907024640/3907024640 idle 0

$ lspci -v
00:1f.2 RAID bus controller: Intel Corporation 82801 SATA Controller [RAID mode]
    Subsystem: Hewlett-Packard Company Device 130b
    Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 93
    I/O ports at c100 [size=8]
    I/O ports at c110 [size=4]
    I/O ports at c108 [size=8]
    I/O ports at c114 [size=4]
    I/O ports at c0c0 [size=32]
    Memory at e3404000 (32-bit, non-prefetchable) [size=2K]
    Capabilities: [80] MSI: Enable+ Count=1/16 Maskable- 64bit-
    Capabilities: [70] Power Management version 3
    Capabilities: [a8] SATA HBA v1.0
    Capabilities: [b0] PCI Advanced Features
    Kernel driver in use: ahci

$ sudo fdisk -l

Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Disk /dev/sda doesn't contain a valid partition table

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Disk /dev/sdb doesn't contain a valid partition table

Disk /dev/sdc: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Disk /dev/sdc doesn't contain a valid partition table

Disk /dev/sdd: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000

Disk /dev/sdd doesn't contain a valid partition table

Disk /dev/sde: 60.0 GB, 60022480896 bytes
255 heads, 63 sectors/track, 7297 cylinders, total 117231408 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000ad848

   Device Boot      Start         End      Blocks   Id  System
/dev/sde1            2048   117229567    58613760   83  Linux

WARNING: GPT (GUID Partition Table) detected on '/dev/mapper/isw_jbbicjigc_Storage'! The util fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/mapper/isw_jbbicjigc_Storage: 6001.2 GB, 6001189847040 bytes
255 heads, 63 sectors/track, 729603 cylinders, total 11721073920 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 65536 bytes / 196608 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/isw_jbbicjigc_Storage doesn't contain a valid partition table

Any ideas on what to try next would be much appreciated.

Answer 1

I would avoid reformatting the drive, as a last possible option.

A similar situation happened with my RAID5 4 drive iOmega device where the content was not viewable aver a failed drive was replaced and restored.

1. Backdoor with FTP to view and transfer data to another large external hard drive. You can look up how to use File Transfer Protocol and how to attempt this separately.
2. Reformat NAS drive into RAID10 or RAID01. This will save you from similar headaches in the future, and allow drive swapping without worries.
3. Transfer data back onto the newly formatted RAID10 device.
4. If step 1 was unsuccessful, good luck.
5. If this does not work and the information is valuable, pay a data recovery specialist ~$2000 or continue to search online.