On Tuesday, 28 December 2021 20:21:32 GMT Dale wrote: > 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=43 > 7,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 > > :-) :-)
I don't think I've come across something like this before. In my case data is lost, occasionally irretrievably. I suppose something has switched blocks on the SD as immutable, probably a controller having a hiccup. You could try blkdiscard to erase blocks directly - but I haven't tried this on an SD. I also haven't tried to know if it will work at all hdparm's secure deletion. However, the best option is to see if the OEM offers a reset app for this particular card and use that.
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