NSA325-v2 - how to restore data without NSA?

Lefty · February 2020

Assuming my NSA325 will crash, but HDD will not. How do I access my data?
Same with data in DAR files on external HDD I've got plugged in via USB to NSA. How to manage that without NSA?

#NAS_Feb_2020

Mijzelf · February 2020

You can connect the disk to any Linux system, and read it.

https://kb.zyxel.com/KB/searchArticle!gwsViewDetail.action?articleOid=013308&lang=EN

About the DAR files, It's an open source archiving system. http://dar.linux.free.fr/ . You should be able to extract that using the freely available tools. However, I never used it, and remember discussions on other forums about extracting difficulties caused by incremental backups.

In your case I would check if you can extract the files on another platforum, and use a different approach when you fail.

Mijzelf · February 2020

You can connect the disk to any Linux system, and read it.

https://kb.zyxel.com/KB/searchArticle!gwsViewDetail.action?articleOid=013308&lang=EN

About the DAR files, It's an open source archiving system. http://dar.linux.free.fr/ . You should be able to extract that using the freely available tools. However, I never used it, and remember discussions on other forums about extracting difficulties caused by incremental backups.

In your case I would check if you can extract the files on another platforum, and use a different approach when you fail.

Lefty · February 2020

Thanks, that's clear.

Damian · May 2020

Hi, I tried exactly that, but no luck. I am operating a NSA325V2 for many years as backup device with two JBOD volumes. The volumes thus are quite old, I guess from around 2012. I removed one of the drives from the NSA, and plugged it into a raspberry pi 4 using a usb adapter running latest raspbian buster. No luck mounting though - sdc2 is missing.: (drive is /dev/sdc)

pi@rpi4:~ $ sudo fdisk -l
[removed irrelevant drives]

Disk /dev/sdc: 2.7 TiB, 3000557895680 bytes, 5860464640 sectors
Disk model: Elements 25A3
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x00000000

Device Boot Start End Sectors Size Id Type
/dev/sdc1 1 4294967295 4294967295 2T ee GPT

Partition 1 does not start on physical sector boundary.

root@rpi4:/home/pi# cat /proc/partitions
major minor #blocks name

   1        0       4096 ram0
   1        1       4096 ram1
   1        2       4096 ram2
   1        3       4096 ram3
   1        4       4096 ram4
   1        5       4096 ram5
   1        6       4096 ram6
   1        7       4096 ram7
   1        8       4096 ram8
   1        9       4096 ram9
   1       10       4096 ram10
   1       11       4096 ram11
   1       12       4096 ram12
   1       13       4096 ram13
   1       14       4096 ram14
   1       15       4096 ram15
179        0   31166976 mmcblk0
179        1     262144 mmcblk0p1
179        2   30900736 mmcblk0p2
   8        0   30031250 sda
   8        1   30031234 sda1
   8       16 976762584 sdb
   8       17 976700872 sdb1

8 32 2930232320 sdc

root@rpi4:/home/pi# parted /dev/sdc1 print
Error: Could not stat device /dev/sdc1 - No such file or directory.
Retry/Cancel? c
root@rpi4:/home/pi# parted /dev/sdc2 print
Error: Could not stat device /dev/sdc2 - No such file or directory.
Retry/Cancel? c
root@rpi4:/home/pi# parted /dev/sdc print
Error: Invalid argument during seek for read on /dev/sdc
Retry/Ignore/Cancel? i
Error: The backup GPT table is corrupt, but the primary appears OK, so that will be used.
OK/Cancel? o
Model: WD Elements 25A3 (scsi)
Disk /dev/sdc: 3001GB
Sector size (logical/physical): 512B/4096B
Partition Table: unknown
Disk Flags:

If I try the same on the NSA; which mounts the device automatically (works perfect), it looks like this:

admin@NSA325:~$ sudo parted /dev/sdb print
Password:
Model: WD30EZRX-00MMMB0 (scsi)
Disk /dev/sdb: 3001GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number Start   End     Size    File system     Name       Flags
1      1049kB 512MB   511MB   linux-swap(v1) mitraswap
2      512MB   3001GB 3000GB                  eexxtt44

Does anyone have a hint for me?

Thanks!!!

Damian

Mijzelf · May 2020

Sector size (logical/physical): 512 bytes / 4096 bytes

Sector size (logical/physical): 512B/512B

I think your USB to SATA convertor is doing bad things™, and converts the sectorsize of disks >2TiB. (For compatibilitiy with Windows XP, you know.), which means the partition table is incompatible (as it addresses in sectors).

You can test that by converting the sectorsize back, using a loopdevice.

losetup --sector-size 512 -P -f /dev/sdb

Now you should see the partitions in /proc/partitions as partitions of the loopdevice. (Probably /dev/loop0)

Damian · May 2020

Thanks for the help! There are loop-partitions, but I was not able to mount them using mount or mdadm. How should I be able to do that?

Damian · May 2020

I verified the process with my Desktop-PC and a Ubuntu Live USB Stick. Reading works fine.

I am interested in this only for failure scenarios (e.g. the Zyxel goes bust and I need to access the backups stored on the JBOD drives). So basically it is good to know how to get it working. But I would just LOVE to find a way to just attach such drives to one of my Raspberry Pi 4s and access the data.

Does anyone know a way, are there SATA/USB bridges allowing this?

Mijzelf · May 2020

Which kernel runs on your RPi? According to the man page --sector-size is supported since 4.14. According to Wikipedia a RPi 4 should run at least 4.19 -if it runs Raspbian.

How does your /proc/partitions look? Any strange messages in dmesg? Does mdadm show useful information when adding --verbose (twice)?

Does mdadm fail, or does the assembled md device not mount? If the latter, again, what does dmesg say? And mount -vv?

It would be nice if you can compare this between Raspbian and Ubuntu live. The outputs should be mainly the same.

Does anyone know a way, are there SATA/USB bridges allowing this?

They exist. Unfortunately there isn't a list. I have read about some brand and type where different chips were used, so one sample works, and another doesn't.

BTW, if you use the disk exclusively with that SATA/USB bridge, there is no problem. 4k sectors are fine, as long as the partition table is created for that. You only get in trouble if you exchange pure Sata with this bridge.

Damian · May 2020

Thanks for the reply! I will check it again on one of the next weekends, I can't pull one of the drives out of the Zyxel right now because of backups running. I will reply with more detail then.

NSA325-v2 - how to restore data without NSA?

Accepted Solution

All Replies

Categories

Consumer Product Help Center