Can't Access Particular SD Card

[ts1971]

Hi,

I am running Ubuntu 20.04 on a Lenovo P70 and all of the sudden an SD card that I use very frequently became unreadable. There are no errors that I see, but when I pop it into the drive nothing happens and if I open a term I don't see anything under /media. All of my other SD cards still work fine. I thought that maybe the card had just gone bad, but as it happens I have what I'm pretty sure is a bit for bit copy of the disk and it also isn't being read. I tried inserting both files into a windows laptop and it complained about the format of both and wanted to reformat (obviously I didn't do that). Shortly before this stopped working I had done a required Ubuntu upgrade; so that's possibly involved here. I will also mention, in case it's relevant, that about the same time that this problem popped up Celluloid / MPV also stopped working.

I really don't want to lose this data; if anyone could point me in the right direction, I'd really appreciate it.


Thanks!

 

[Condobloke]

G'day ts1971, Welcome to Linux.org

Just a random suggestion. Can you use a bootable USB stcik to boot your pc....and then insert your sd card.

Any joy ?

 

[DexTheDog]

I cant get my micro sd cards to work on linux though I haven't tried that hard. So I guess my question is the sd card that wont work micro?

 

[NorthWest]

ts1971 wrote:

I am running Ubuntu 20.04 on a Lenovo P70 and all of the sudden an SD card that I use very frequently became unreadable. There are no errors that I see, but when I pop it into the drive nothing happens and if I open a term I don't see anything under /media.

If you can determine that the kernel sees the SD card, then you should be able to mount it manually since it's been readable in the past, and if not damaged.
You can check what the kernel sees in a number of ways. One is to run, as root in a terminal:

dmesg -w

and watch the terminal as you push the card into the socket. If the kernel can see it, it will output identifying data, and if the kernel detects something in error, it will output some message to that effect. To stop the "dmesg -w" output when you are finished with it, hit cntl+c. If the card is seen without errors, then you can run:

lsblk

to find its device name and then mount it wherever you like as root, e.g.

mount -t auto /dev/sdX# /mnt

and then navigate to /mnt in the filesystem and the cards contents should be accessible. Usually "X" will be a letter and "#" a partition number where the data is stored. You don't need to be root to see what's on /mnt.

If the kernel can't see the card, there's not much that can be done about it in the normal way, but there are some things that can be done using some specialised programs like testdisk.

 

[ts1971]

I cant get my micro sd cards to work on linux though I haven't tried that hard. So I guess my question is the sd card that wont work micro?

This particular card is not, though I have never had any trouble with micro sd cards on my Ubuntu system.

 

[ts1971]

G'day ts1971, Welcome to Linux.org

Just a random suggestion. Can you use a bootable USB stcik to boot your pc....and then insert your sd card.

Any joy ?

I don't currently have one, but maybe it makes sense to put one together. It seems like a useful thing to have!

 

[ts1971]

ts1971 wrote:

If you can determine that the kernel sees the SD card, then you should be able to mount it manually since it's been readable in the past, and if not damaged.
You can check what the kernel sees in a number of ways. One is to run, as root in a terminal:

dmesg -w

and watch the terminal as you push the card into the socket. If the kernel can see it, it will output identifying data, and if the kernel detects something in error, it will output some message to that effect. To stop the "dmesg -w" output when you are finished with it, hit cntl+c.

Thanks for this. According to dmesg it looks like the kernel *can* see the card:

[81172.517549] mmc0: cannot verify signal voltage switch
[81172.640537] mmc0: new ultra high speed SDR104 SDHC card at address 59b4
[81172.641466] mmcblk0: mmc0:59b4 SD32G 29.5 GiB
[81172.657702]  mmcblk0: p1

If the card is seen without errors, then you can run

lsblk

to find its device name and then mount it wherever you like as root, e.g.

Here is the output of lsblk.

jason@jason-ThinkPad-P70:~$ sudo lsblk
NAME                  MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
loop0                   7:0    0     4K  1 loop /snap/bare/5
loop1                   7:1    0   107M  1 loop /snap/blablaland-desktop/3
loop2                   7:2    0 110.7M  1 loop /snap/core/12821
loop3                   7:3    0  55.5M  1 loop /snap/core18/2344
loop4                   7:4    0  61.9M  1 loop /snap/core20/1405
loop5                   7:5    0  61.9M  1 loop /snap/core20/1376
loop6                   7:6    0  55.5M  1 loop /snap/core18/2284
loop7                   7:7    0 110.8M  1 loop /snap/core/12725
loop8                   7:8    0 169.5M  1 loop /snap/emacs/1422
loop9                   7:9    0 102.8M  1 loop /snap/flasharch/12
loop10                  7:10   0  93.4M  1 loop /snap/flasharch/13
loop11                  7:11   0 140.7M  1 loop /snap/gnome-3-26-1604/102
loop12                  7:12   0 140.7M  1 loop /snap/gnome-3-26-1604/104
loop13                  7:13   0 164.8M  1 loop /snap/gnome-3-28-1804/161
loop14                  7:14   0 169.5M  1 loop /snap/emacs/1439
loop15                  7:15   0  42.7M  1 loop /snap/freecell-solitaire/2
loop16                  7:16   0 260.7M  1 loop /snap/kde-frameworks-5-core18/32
loop17                  7:17   0   2.5M  1 loop /snap/gnome-system-monitor/169
loop18                  7:18   0 162.9M  1 loop /snap/gnome-3-28-1804/145
loop19                  7:19   0 247.9M  1 loop /snap/gnome-3-38-2004/87
loop20                  7:20   0  65.1M  1 loop /snap/gtk-common-themes/1515
loop21                  7:21   0 295.7M  1 loop /snap/vlc/2344
loop22                  7:22   0 152.2M  1 loop /snap/skype/203
loop23                  7:23   0   219M  1 loop /snap/gnome-3-34-1804/72
loop24                  7:24   0 248.8M  1 loop /snap/gnome-3-38-2004/99
loop25                  7:25   0    51M  1 loop /snap/snap-store/547
loop26                  7:26   0  93.9M  1 loop /snap/mpv/1
loop27                  7:27   0  65.2M  1 loop /snap/gtk-common-themes/1519
loop28                  7:28   0   2.5M  1 loop /snap/gnome-system-monitor/174
loop29                  7:29   0 152.4M  1 loop /snap/skype/206
loop30                  7:30   0   219M  1 loop /snap/gnome-3-34-1804/77
loop31                  7:31   0   324M  1 loop /snap/telegram-desktop/3544
loop32                  7:32   0   324M  1 loop /snap/telegram-desktop/3530
loop33                  7:33   0  54.2M  1 loop /snap/snap-store/558
sda                     8:0    0 238.5G  0 disk
├─sda1                  8:1    0   487M  0 part /boot
├─sda2                  8:2    0     1K  0 part
└─sda5                  8:5    0   238G  0 part
  ├─ubuntu--vg-root   253:0    0 206.6G  0 lvm  /
  └─ubuntu--vg-swap_1 253:1    0  31.4G  0 lvm  [SWAP]
sr0                    11:0    1  1024M  0 rom 
mmcblk0               179:0    0  29.6G  0 disk
└─mmcblk0p1           179:1    0  29.6G  0 part

Frankly, I'm not sure which device, if any, is the sd card. sd1, sd2, sd5 are all partitions on my hard drive, right? Would it be mmcblk0p1?

mount -t auto /dev/sdX# /mnt

and then navigate to /mnt in the filesystem and the cards contents should be accessible. Usually "X" will be a letter and "#" a partition number where the data is stored. You don't need to be root to see what's on /mnt.

If the kernel can't see the card, there's not much that can be done about it in the normal way, but there are some things that can be done using some specialised programs like testdisk.

I've tried various permutations of the mount command, but can't seem to get it right.

Thanks again for your help so far!

 

[NorthWest]

The SD card partition to try and mount is /dev/mmcblk0p1. You could check in the /dev directory to see that it's there. I would try, as root:

mount -t auto /dev/mmcblk0p1 /mnt

Hopefully that should let you read it when you navigate to /mnt. If you want to write to it, you might need to unmount and mount it again with the extra option: -o umask=0

 

[Condobloke]

You are in the middle of things with NorthWest....don't stop, it may well lead to the solution you need.

Dont forget

G'day ts1971, Welcome to Linux.org

Just a random suggestion. Can you use a bootable USB stcik to boot your pc....and then insert your sd card.

Any joy ?

I don't currently have one, but maybe it makes sense to put one together. It seems like a useful thing to have!

It was maybe used to install linux on your pc ??

Easy to make one...just open a topic later and we can tell you how.