Trying to read a a old raid 1 drive connected via USB

General system Kernel, boot, graphics & hardware
1

Hello friends,
I have old raid 1 mirror drives. However the container of the HDs is broken. I am trying to read the content of the drive using mdadm, but it is not working as I expect.

sdb is added to /dev when the usb cable is connected, but if I try to mount it I get:

mount: /home: special device /dev/sdb does not exist.

After cable connection the following items are added to lsusb:

Bus 001 Device 009: ID 14cd:168a Super Top Elecom Co., Ltd MR-K013 Multicard Reader
Bus 001 Device 008: ID 05e3:0608 Genesys Logic, Inc. Hub

Gparted does not sees the drive.

dmesg contains the following

[   50.772950] usb 1-1.2: new high-speed USB device number 6 using ehci-pci
[   51.065072] usb 1-1.2: device descriptor read/64, error -71
[   51.270405] usb 1-1.2: New USB device found, idVendor=05e3, idProduct=0608, bcdDevice=85.36
[   51.270418] usb 1-1.2: New USB device strings: Mfr=0, Product=1, SerialNumber=0
[   51.270422] usb 1-1.2: Product: USB2.0 Hub
[   51.271383] hub 1-1.2:1.0: USB hub found
[   51.271825] hub 1-1.2:1.0: 4 ports detected
[   51.552940] usb 1-1.2.4: new high-speed USB device number 7 using ehci-pci
[   51.651729] usb 1-1.2.4: New USB device found, idVendor=14cd, idProduct=168a, bcdDevice= 0.01
[   51.651744] usb 1-1.2.4: New USB device strings: Mfr=1, Product=3, SerialNumber=2
[   51.651748] usb 1-1.2.4: Product: USB Mass Storage Device
[   51.651751] usb 1-1.2.4: Manufacturer: USB Device  
[   51.651754] usb 1-1.2.4: SerialNumber: 816820130806
[   51.675677] usb-storage 1-1.2.4:1.0: USB Mass Storage device detected
[   51.675815] scsi host6: usb-storage 1-1.2.4:1.0
[   51.675916] usbcore: registered new interface driver usb-storage
[   51.682163] usbcore: registered new interface driver uas
[   52.679665] scsi 6:0:0:0: Direct-Access     USB Mass  Storage Device  1.00 PQ: 0 ANSI: 0
[   52.680164] sd 6:0:0:0: Attached scsi generic sg1 type 0
[   52.681395] sd 6:0:0:0: [sdb] Media removed, stopped polling
[   52.683466] sd 6:0:0:0: [sdb] Attached SCSI removable disk

Any idea?
best

2

So, physically two disk drives?

That’s one drive - what about the other one?

Why are you mounting to /home ?

What does ls -l /dev/sdb show? Did you create it in some way using mdadm? If so, what did you do?

3

Many thanks Jonathon,

That’s one drive - what about the other one?

The other one behaves just the same

Why are you mounting to /home ?

Well, no special reason, just to test and copy the files

What does ls -l /dev/sdb show?

[f@tablet ~]$ ls -l /dev/sdb
brw-rw---- 1 root disk 8, 16 mar  3 18:39 /dev/sdb

Did you create it in some way using mdadm?

It already existed just connecting the USB cable, but without the USB cable connection sdb does not exists

Best

4

OK, so as a two-disk RAID device you can’t just mount one disk to extract data from it - you need two devices to reconstruct it.

Connect them both and then see what mdadm says.

5

OK, so as a two-disk RAID device you can’t just mount one disk to extract data from it - you need two devices to reconstruct it.

Connect them both and then see what mdadm says.

No Jonathon this is raid 1 mirror and the two drives are identical. I already did that in the past for a very similar situation and it worked with just one drive. Raid 1 is done just for that: if one drive breaks, you still have the other with the full set of data.

But these raid enclosures are too weak. I’ll never try again with raid. They break when you need them and recovering the data is really complicated as we are seeing with this thread

6

OK, so if you don’t want to connect both drives then let’s go back to this:

Why isn’t mdadm working as you expect?

Also, what is different than when you did this

?

7

The following command gives no result:

[f@tablet ~]$ sudo mdadm --detail --scan
[f@tablet ~]$

the following command ends with errors:

 sudo mdadm  --assemble --force --run  /dev/md5 /dev/sdb
mdadm: cannot open device /dev/sdb: No medium found
mdadm: /dev/sdb has no superblock - assembly aborted

Well a lot of time passed, but md5 was created and I was able to mount it and copy the files to another medium.