Howdy, As some may recall, I have quite a few deer trail cameras that use SD memory cards. On occasion some of the cards start acting weird. I've got one that is really weird. Usually I just replace them but this one is a bit of a puzzle I'd like to solve. When it stopped working, it had a dozen or so short videos on it that are about 30MBs on average. Some color and large, some black and white night vision and fairly small. When it stopped working, I tried to reformat the thing. The files remained even after that. I then ran dd and zeroed the thing, files still there even tho dd reported no problems. I then used this GUI disk program that tests memory cards and it claims the card is fine. It writes files to it, reads them back. I also used it to reformat the card. The original videos are still there. Today I decided to play with it again. I ran this dd command on the stick.
root@fireball / # dd if=/dev/zero of=/dev/sdh bs=4K conv=notrunc oflag=direct status=progress 31907364864 bytes (32 GB, 30 GiB) copied, 3956 s, 8.1 MB/s dd: error writing '/dev/sdh': No space left on device 7791745+0 records in 7791744+0 records out 31914983424 bytes (32 GB, 30 GiB) copied, 3956.94 s, 8.1 MB/s root@fireball / # As you can see, no errors. It wrote zeros until it ran out of space. Guess what, the original videos are still on the card. File listing: root@fireball / # ls -al /run/media/dale/2140-2E00/DCIM/100MEDIA/* -rw-r--r-- 1 dale users 0 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/AAAAAAAA.AAA -rw-r--r-- 1 dale users 0 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/BBBBBBBB.BBB -rw-r--r-- 1 dale users 14335272 May 2 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0823.AVI -rw-r--r-- 1 dale users 50843576 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0824.AVI -rw-r--r-- 1 dale users 53137560 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0825.AVI -rw-r--r-- 1 dale users 18398504 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0826.AVI -rw-r--r-- 1 dale users 18922808 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0827.AVI -rw-r--r-- 1 dale users 18332888 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0828.AVI -rw-r--r-- 1 dale users 18726200 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0829.AVI -rw-r--r-- 1 dale users 18332920 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0830.AVI -rw-r--r-- 1 dale users 18005288 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0831.AVI -rw-r--r-- 1 dale users 17612088 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0832.AVI -rw-r--r-- 1 dale users 17153336 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0833.AVI -rw-r--r-- 1 dale users 16694584 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0834.AVI -rw-r--r-- 1 dale users 0 May 6 2018 /run/media/dale/2140-2E00/DCIM/100MEDIA/WGI_0835.AVI root@fireball / # The zero byte files are broken, my first clue way back that the card needed replacing. I see no errors in dmesg or messages. Usually the cards produce errors and it remounts read only. Not in this case tho. Mount info: root@fireball / # mount | grep sdh /dev/sdh1 on /run/media/dale/2140-2E00 type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=100,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro,uhelper=udisks2) root@fireball / # In the past, I've at times been able to copy the files off other cards going bad but it stays read only. Reformating fails etc etc. Sometimes, it just plain doesn't work. Almost always tho I get a error of some kind in messages or dmesg if not both. This one tho, it's just plain weird. No errors but nothing removes the files either. Oh, I've checked the lock button. It's not locked. It is shown that way in dmesg as well. [2592841.808336] sd 10:0:0:2: [sdh] Write Protect is off Obviously I'm not going to trust this thing. It will end up in the trash but, does this make sense to anyone else? Of all the ones I've worn out, this is the only one that behaves this way. I'd at least expect the format to fail or it only mount read only. At least some sort of error anyway. Thoughts? Dale :-) :-)
