Recovering RAID From ReadyNAS Ultra 6

[leethompson]

The Problem

On 10/5/2021 my ReadyNAS Ultra 6 suddenly powered off. I suspect it's the PSU because when powered it will flash the power and activity LED for a fraction of a second and then go out again. It is formatted X-RAID2 (RAID 6).

What I've Done So far

I've imaged drives 1-4 thinking I don't really need drives 5 and 6 (also the USB drive I'm using for images only would have room for disks 1-5).

All I've been able to recover so far are the RAIDiator 4.22 files, logs and configuration. (I have the entire root tree). I have only a passing knowledge of Linux & Debian.

I bought R-Studio (at the $79 level) and I can see files on the various disks to some degree but I am currently unable to even figure out how to rebuild the array (specifically I'm interested in md2 and apparently a md3 which appear to make up my data).

I haven't been able to make heads or tails of creating the virtual raid within R-Studio. Do I need drives 5 and 6? How do I determine the right configuration settings?

Help... please.


Additional Data

Additional information appears below taken from the config and log files of the downed unit.

It appears there are 3 RAID volumes according to mdconfig and mdstat:

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md2 : active raid6 sda3[0] sdf3[5] sde3[4] sdd3[3] sdc3[2] sdb3[1]
      7795170816 blocks super 1.2 level 6, 64k chunk, algorithm 2 [6/6] [UUUUUU]
      
md1 : active raid6 sda2[0] sdf2[5] sde2[4] sdd2[3] sdc2[2] sdb2[1]
      2096896 blocks super 1.2 level 6, 64k chunk, algorithm 2 [6/6] [UUUUUU]
      
md0 : active raid1 sda1[0] sdf1[5] sde1[4] sdd1[3] sdc1[2] sdb1[1]
      4193268 blocks super 1.2 [6/6] [UUUUUU]

Each drive, however, has 4 partitions.

(This is sda's but they're all the same except for the serial number obviously):

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Disk /dev/sda: 5860533168 sectors, 2.7 TiB
Logical sector size: 512 bytes
Disk identifier (GUID): 8B719D4B-D3A3-4D53-8639-1C24B252EE49
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 5860533134
Partitions will be aligned on 8-sector boundaries
Total free space is 4133 sectors (2.0 MiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1              64         8388671   4.0 GiB     FD00  
   2         8388672         9437247   512.0 MiB   FD00  
   3         9437248      3907025072   1.8 TiB     FD00  
   4      3907025080      5860529038   931.5 GiB   FD00  

md3 only appears in the lvm config, it may be the snapshot now that I think of it.

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creation_host = "REDACTED"	# Linux NAS03 2.6.37.6.RNx86_64.2.4 #1 SMP Thu May 28 16:29:46 PDT 2015 x86_64
creation_time = 1632575423	# Sat Sep 25 06:10:23 2021

c {
	id = "ieDuFK-AYOx-TRRc-1Lio-1AKH-0bDS-N2eBIT"
	seqno = 476
	status = ["RESIZEABLE", "READ", "WRITE"]
	extent_size = 131072		# 64 Megabytes
	max_lv = 0
	max_pv = 0

	physical_volumes {

		pv0 {
			id = "H2pe8n-q5j6-1DY1-NPyW-D7bW-0IuL-AZZ9A6"
			device = "/dev/md2"	# Hint only

			status = ["ALLOCATABLE"]
			pe_start = 7680
			pe_count = 118944	# 7.25977 Terabytes
		}

		pv1 {
			id = "XVzCLO-vWGQ-ir4K-n409-Go1q-86kE-w2XxUC"
			device = "/dev/md3"	# Hint only

			status = ["ALLOCATABLE"]
			pe_start = 384
			pe_count = 59616	# 3.63867 Terabytes
		}
	}

	logical_volumes {

		c {
			id = "73QkJh-pwy6-nvh9-wlg0-zaof-W9Kj-5cGu79"
			status = ["READ", "WRITE", "VISIBLE"]
			segment_count = 2

			segment1 {
				start_extent = 0
				extent_count = 118944	# 7.25977 Terabytes

				type = "striped"
				stripe_count = 1	# linear

				stripes = [
					"pv0", 0
				]
			}
			segment2 {
				start_extent = 118944
				extent_count = 59456	# 3.62891 Terabytes

				type = "striped"
				stripe_count = 1	# linear

				stripes = [
					"pv1", 0
				]
			}
		}
	}
}

[Alt]

What is the file system of this RAID?

[leethompson]

ext4 according to fstab
(/dev/c/c) is the user data partition. It's an LVM object containing /dev/md2 (data) and /dev/md3(snapshot). Well I'm 60% sure md3 is the snapshot.

fstab:

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/dev/md0           /                    ext3       defaults,noatime,nodiratime      0      0
proc               /proc                proc       defaults          0      0
/dev/md1           swap                 swap       defaults          0      0
/dev/c/c           /c                   ext4       defaults,acl,user_xattr,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv1,noatime,nodiratime      0      2
/public            /home/ftp/public     bind       bind              0      0

mtab:

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/dev/md0 / ext3 rw,noatime,nodiratime 0 0
proc /proc proc rw 0 0
sysfs /sys sysfs rw 0 0
devpts /dev/pts devpts rw 0 0
tmpfs /ramfs ramfs rw 0 0
tmpfs /USB tmpfs rw,size=16k 0 0
usbfs /proc/bus/usb usbfs rw 0 0
/dev/c/c /c ext4 rw,noatime,nodiratime,acl,user_xattr,usrjquota=aquota.user,grpjquota=aquota.group,jqfmt=vfsv1 0 0
/c/public /home/ftp/public bind rw,bind 0 0
nfsd /proc/fs/nfsd nfsd rw 0 0
configfs /sys/kernel/config configfs rw 0 0

OS:

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RAIDiator v4.2.28 (based on Debian 4)

[Alt]

My understanding is that you'd better have all disk imaged. If that isn't an option, you need to add 2 extra "missing disk" objects to the virtual LVM object R-Studio should created automatically.
Did R-Studio created such object when you connected the 4 disk images? If yes, what color was that object?
You may read more about working with virtual LVM objects in our on-line help: Linux LVM/LVM2.

[leethompson]

Did not see any LVM anything in R-Studio, just "mdadm Protective Partition" entries (4 per disk, which should be correct), and then these wierd "virt-mdadm-(some hex number):# i.e.

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virt-mdadm-001F33EA9C08:0

[Alt]

Sorry for the long delay. We're investigating into this problem.

[leethompson]

No worries, I'm imaging disks 5 and 6 and that is not a fast process (USB SATA dock writing to a USB drive).

Might be done Friday/Saturday ish assuming nothing weird happens.

What might be an interesting feature for R-Studio is if you have any config files from the original NAS device, have it read that and help it figure out how to map it? I'm not sure how useful they are though since you'd have to map stuff like /dev/sda etc for it to have any meaning.

I'm somewhat lucky in the array that's down I've depreciated for about 6 months as I've been setting up a newer, larger Synology to migrate to. (And some migration has taken place.) (It's been a slower than normal migration since it's also been a chance to reorganize, etc) So this is mostly older files that hadn't been copied over yet.

[Alt]

Please, send me System info when you've done the cloning. We'll try to figure out what is wrong.
Tools -> Save System Info
Send to: raptorbck (at) gmail (dot) com

[leethompson]

I'm going to assume that all 6 images should be opened as well.

I am new to your software I hope I'm not just doing something stupid lol

Anyway disk 6 image ETA is tomorrow afternoon so more then.

[leethompson]

Image finished, e-mail sent.

Feature request: It would be helpful if we could re-name the partitions within R-Studio, having 4 mdadm Protective Partition 4 times per disk for 6 disks is kind of hard to keep track of.