Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 26/03/17 17:24, tu...@posteo.de wrote: On 03/26 04:50, Bill Kenworthy wrote: On 26/03/17 15:26, tu...@posteo.de wrote: On 03/26 03:04, Bill Kenworthy wrote: On 26/03/17 14:25, tu...@posteo.de wrote: On 03/26 05:50, tu...@posteo.de wrote: On 03/26 11:21, Adam Carter wrote: Step 1: dd the contents into an image ddrescue is probably a better option than plain dd. step 2: put the sdcard to one side. step 3: loopback mount a copy of the image (not the original) step 4: try recovering the filesystem on the loopback, if it fails ... try something else on another image copy Yep, once you've got the image mounted loopback, you can run testdisk/photorec depending on how bad it is. Hi all, thanks a lot for all help! :) Currently I am ddresucueing the flashcard to the harddisc. Next I will try to mount the sdcard. What reliable sdcard-reader can one recommend ? (...sorry if this sentence sounds harsh...I it by no means meant that way...I am no native speaker... :) Cheers Meino Hi, Is the assumption correct, that -- if ddrescue could read each partitions of the sdcard without stuttering, retries and errors -- the sdcard itsself is ok and "only" the logical structure (fs, superblock etc) got damaged? Or do I overlook something? (Background: I dont want to put a sdcard into the bin, if fdisking & reformatting that beast would gives me back an ok media...) Cheers Meino The dd gets you the best chance to work on the data before it completely fails. In my experience the sdcard will only get worse ending with total failure - if it hasn't already. If the dd dump comes up rubbish and cant be recovered, the actual sdcard will be worse. You can run "strings" against the image to see if there is any text in there (or even cat the /dev/sdcard node through strings) to see if the bits are still there. I dont know of a cdparanoia type recovery utility for sdcards but I suspect sdcard design means that approach wont work. BillK Hi Bill, I got mixed results: There are three partitions on the sdcard from which I could fully recover (even mount it directly via loop device) the first and the third one. The second one is screwed up. Running fsch.ext4 against the image it starts with "bad superblock" and suggests two alternatives. I started fsch.ext4 again while using -b to define the alternate superblock and it starts to ask me *zillions of question, which I all answered with 'yes' in a first attempt (I have a backup of the image...). The result was an image, which I could mount again. But beside 'lost+found' with some small rests of something which may be files in a previous life nothing was there Currently it looks to me, that something has totally messed up the fs there. What do you think? Cheers Meino Sounds like its toast :( I have never had a lot of luck with any of the ext file systems - you have to baby them and they corrupt very easily compared to others. I try and avoid them ... BillK Hi Bill, ...the SDcard is for my Android tablet, which runs kernel 3.6.x.something (Lollipop) if I remember correctly. With the App Linux Deploy I installed Linux on another partition of the sdcard and used to chroot into it. With what filesystem did you made good experiences of, Bill? My GENTOO PC (with which I am currently writing this email) also uses ext4...and your last mail makes me nervous...very nervous... For my tablet I have to use an filesystem, which is supported by and compiled into the kernel. Unfortunately, there is no alternative Android build for this tablet... In this case it is ext4 and vfat...and of that both I think ext4 is better... Cheers Meino I used to prefer reiserfs ... more robust in some ways, less in others ... BUT I almost always was able to rescue files or whole filesystems with reiserfs, not so with ext*. These days I prefer btrfs ... again not perfect but with OS disks are single and the rest are bcache/ssd fronted btrfs raid10's my main issue is running out of space. Problems with the ext series were inability to deal with dirvish backup (corrupted), running out of inodes, terminal corruption when running out of space, silent corruption with hibernation, data loss/corruption on abrupt power loss, and it goes on ... Current sdcards are either vfat for win compatibility (no choice) or btrfs (raspberry pi). Just turned off my older rpi model 1B which is ext 4 earlier this morning - been corrupted and reimaged a few times! File systems seem to be very much YMMV - each use, load and environment present a different set of requirements and problems. BillK
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On Sunday 26 Mar 2017 20:37:08 Adam Carter wrote: > I did that already. > > > Gives me a lot of files with unrelated names. > > Think of your GENTOO box with all names renamed > > to something like > > > > [index number].[filetype] > > > > . So you got back your data but cannot use > > it, since the names got lost. > > > > For images this is not a big deal...display them > > and you know probably how to rename them back > > to something useful. > > > > But what file is (for example) > > > > -rwxr-xr-x 1 root root 4083 2011-11-22 03:46 file002873.bin > > Does file file002873.bin provide any help? > > And yes, its a real pain to loose the filenames! Some years ago I had to revive a removable drive that someone had repeatedly snatched out of the machine without unmounting it first. I tried photorec and pals and had the same impenetrable maze of unhelpful file names as Adam's. I know it's not much help, but I eventually found another utility that just swept through and put everything back together again, humpty- dumpty fashion. I wish I could remember what the utility was. Sorry. But it is out there somewhere in Google-land. -- Regards Peter
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
Hi tuxic, That looks like an output from photorec. Generally photorec only reads the whole disk block by block, when it finds information in the filesystem's metadata - either inode table or inodes themselves - you're lucky and you get filenames, otherwise you only get that kind of output. Consider that all those items might as well be deleted items, so you might be getting back a lot of cruft. I never had to use the functionality so I cannot comment on how good it works, but testdisk allows you to restore partitions by scanning the entire disk/image searching for superblocks and partition metadata. That might give you a chance of restoring the superblock of the partition and salvaging at least some part of the data. See a guide on testdisk's official website -> http://www.cgsecurity.org/wiki/TestDisk_Step_By_Step Consider that by default ext4 partitions should have superblock backups spread out at fixed intervals during the filesystem creation, so this should work better than trying to blindly carve the data out of the partition. Before applying fixes to the image file make a backup in case something gets screwed up :-) Testdisk might detect additional stuff that looks like partition info, but it's not. Il giorno dom 26 mar 2017 alle ore 11:37 ha scritto: > On 03/26 08:10, Adam Carter wrote: > > > Currently I am ddresucueing the flashcard to the harddisc. > > >>> Next I will try to mount the sdcard. > > >>> > > >>> > > I hope you meant to say "mount the sdcard image". Once ddrescue has done > > its best, you wont try to use the sdcard again. > > > > Also, you probably want to copy the image first, because when you try to > > fix it you will perform writes, and you dont want to lock yourself out of > > other recovery options by making potentially damaging writes. > > > > > > > What reliable sdcard-reader can one recommend ? > > >>> > > >> > > I'm not sure what you mean here given that you're making an image with > > ddrescue. > > > > Is the assumption correct, that -- if ddrescue could read each > > >> partitions of the sdcard without stuttering, retries and errors -- > > >> > > > the sdcard itsself is ok and "only" the logical structure > > >> (fs, superblock etc) got damaged? > > >> Or do I overlook something? > > >> > > > > > If ddrescue can read it cleanly with no retries (in which case it will > > offer no benefit over dd) then yes, I agree. However, given the cost of a > > card and the cost of your time and the risk to your data, I wouldnt be > > using it. > > > > > > > I dont know of a cdparanoia type recovery utility for sdcards but I > > > suspect sdcard design means that approach wont work. > > > > > > > I would just use photorec against a copy of the image. I have done this > in > > the past and recovered many files from a ddrescued image of a failing USB > > drive, however, all the filenames were lost. > > Hi, > > I copied the image of course and umounted the sdcard as soon as > possible. > > As in my previous posting, as long the recovered files are images, > the lost of filenames my be annoying... > But in case of files of a Android system (from which the sdcard > originates) the lost of filenames is equivaltent to the lost of > the file itsself... > > Cheers > Meino > > > > >
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
I did that already. > Gives me a lot of files with unrelated names. > Think of your GENTOO box with all names renamed > to something like > > [index number].[filetype] > > . So you got back your data but cannot use > it, since the names got lost. > > For images this is not a big deal...display them > and you know probably how to rename them back > to something useful. > > But what file is (for example) > > -rwxr-xr-x 1 root root 4083 2011-11-22 03:46 file002873.bin > Does file file002873.bin provide any help? And yes, its a real pain to loose the filenames!
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 03/26 08:10, Adam Carter wrote: > > Currently I am ddresucueing the flashcard to the harddisc. > >>> Next I will try to mount the sdcard. > >>> > >>> > I hope you meant to say "mount the sdcard image". Once ddrescue has done > its best, you wont try to use the sdcard again. > > Also, you probably want to copy the image first, because when you try to > fix it you will perform writes, and you dont want to lock yourself out of > other recovery options by making potentially damaging writes. > > > > What reliable sdcard-reader can one recommend ? > >>> > >> > I'm not sure what you mean here given that you're making an image with > ddrescue. > > Is the assumption correct, that -- if ddrescue could read each > >> partitions of the sdcard without stuttering, retries and errors -- > >> > > the sdcard itsself is ok and "only" the logical structure > >> (fs, superblock etc) got damaged? > >> Or do I overlook something? > >> > > > If ddrescue can read it cleanly with no retries (in which case it will > offer no benefit over dd) then yes, I agree. However, given the cost of a > card and the cost of your time and the risk to your data, I wouldnt be > using it. > > > > I dont know of a cdparanoia type recovery utility for sdcards but I > > suspect sdcard design means that approach wont work. > > > > I would just use photorec against a copy of the image. I have done this in > the past and recovered many files from a ddrescued image of a failing USB > drive, however, all the filenames were lost. Hi, I copied the image of course and umounted the sdcard as soon as possible. As in my previous posting, as long the recovered files are images, the lost of filenames my be annoying... But in case of files of a Android system (from which the sdcard originates) the lost of filenames is equivaltent to the lost of the file itsself... Cheers Meino
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 03/26 08:18, Adam Carter wrote: > > I got mixed results: There are three partitions on the sdcard from > > which I could fully recover (even mount it directly via loop device) > > the first and the third one. > > > > The second one is screwed up. > > > > Running fsch.ext4 against the image it starts with "bad superblock" > > and suggests two alternatives. > > > > I started fsch.ext4 again while using -b to define the alternate > > superblock and it starts to ask me *zillions of question, which > > I all answered with 'yes' in a first attempt (I have a backup of the > > image...). > > The result was an image, which I could mount again. > > But beside 'lost+found' with some small rests of something which > > may be files in a previous life nothing was there... > > > In that case its photorec time against the copy of the image (see previous > note about only working on a copy - the changes that fsck makes may > compromise photorec's efficacy). Probably worth reading the testdisk and > photorec man pages first. I did that already. Gives me a lot of files with unrelated names. Think of your GENTOO box with all names renamed to something like [index number].[filetype] . So you got back your data but cannot use it, since the names got lost. For images this is not a big deal...display them and you know probably how to rename them back to something useful. But what file is (for example) -rwxr-xr-x 1 root root 4083 2011-11-22 03:46 file002873.bin which is located somewhere in the Marianna trench of an Android system??? Hm... Currently I am playing with different kinds of "get lost" it seems...
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 03/26 04:50, Bill Kenworthy wrote: > On 26/03/17 15:26, tu...@posteo.de wrote: > > On 03/26 03:04, Bill Kenworthy wrote: > > > On 26/03/17 14:25, tu...@posteo.de wrote: > > > > On 03/26 05:50, tu...@posteo.de wrote: > > > > > On 03/26 11:21, Adam Carter wrote: > > > > > > Step 1: dd the contents into an image > > > > > > > > > > > > ddrescue is probably a better option than plain dd. > > > > > > > > > > > > step 2: put the sdcard to one side. > > > > > > > step 3: loopback mount a copy of the image (not the original) > > > > > > > step 4: try recovering the filesystem on the loopback, if it > > > > > > > fails ... try > > > > > > > something else on another image copy > > > > > > > > > > > > > > > > > > Yep, once you've got the image mounted loopback, you can run > > > > > > testdisk/photorec depending on how bad it is. > > > > > > > > > > Hi all, > > > > > > > > > > thanks a lot for all help! :) > > > > > > > > > > Currently I am ddresucueing the flashcard to the harddisc. > > > > > Next I will try to mount the sdcard. > > > > > > > > > > What reliable sdcard-reader can one recommend ? > > > > > (...sorry if this sentence sounds harsh...I it by no means meant > > > > > that way...I am no native speaker... :) > > > > > > > > > > Cheers > > > > > Meino > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > Is the assumption correct, that -- if ddrescue could read each > > > > partitions of the sdcard without stuttering, retries and errors -- > > > > the sdcard itsself is ok and "only" the logical structure > > > > (fs, superblock etc) got damaged? > > > > Or do I overlook something? > > > > > > > > (Background: I dont want to put a sdcard into the bin, if > > > > fdisking & reformatting that beast would gives me back an ok > > > > media...) > > > > > > > > Cheers > > > > Meino > > > > > > > > > > > > > > > > > > > > > > The dd gets you the best chance to work on the data before it completely > > > fails. In my experience the sdcard will only get worse ending with total > > > failure - if it hasn't already. > > > > > > If the dd dump comes up rubbish and cant be recovered, the actual sdcard > > > will be worse. You can run "strings" against the image to see if there is > > > any text in there (or even cat the /dev/sdcard node through strings) to > > > see > > > if the bits are still there. > > > > > > I dont know of a cdparanoia type recovery utility for sdcards but I > > > suspect > > > sdcard design means that approach wont work. > > > > > > BillK > > > > > > > > > > > > > Hi Bill, > > > > I got mixed results: There are three partitions on the sdcard from > > which I could fully recover (even mount it directly via loop device) > > the first and the third one. > > > > The second one is screwed up. > > > > Running fsch.ext4 against the image it starts with "bad superblock" > > and suggests two alternatives. > > > > I started fsch.ext4 again while using -b to define the alternate > > superblock and it starts to ask me *zillions of question, which > > I all answered with 'yes' in a first attempt (I have a backup of the > > image...). > > The result was an image, which I could mount again. > > But beside 'lost+found' with some small rests of something which > > may be files in a previous life nothing was there > > > > Currently it looks to me, that something has totally messed up the fs > > there. > > > > What do you think? > > > > Cheers > > Meino > > > > > > > > > > > Sounds like its toast :( > > I have never had a lot of luck with any of the ext file systems - you have > to baby them and they corrupt very easily compared to others. I try and > avoid them ... > > BillK > > > Hi Bill, ...the SDcard is for my Android tablet, which runs kernel 3.6.x.something (Lollipop) if I remember correctly. With the App Linux Deploy I installed Linux on another partition of the sdcard and used to chroot into it. With what filesystem did you made good experiences of, Bill? My GENTOO PC (with which I am currently writing this email) also uses ext4...and your last mail makes me nervous...very nervous... For my tablet I have to use an filesystem, which is supported by and compiled into the kernel. Unfortunately, there is no alternative Android build for this tablet... In this case it is ext4 and vfat...and of that both I think ext4 is better... Cheers Meino
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
> I got mixed results: There are three partitions on the sdcard from > which I could fully recover (even mount it directly via loop device) > the first and the third one. > > The second one is screwed up. > > Running fsch.ext4 against the image it starts with "bad superblock" > and suggests two alternatives. > > I started fsch.ext4 again while using -b to define the alternate > superblock and it starts to ask me *zillions of question, which > I all answered with 'yes' in a first attempt (I have a backup of the > image...). > The result was an image, which I could mount again. > But beside 'lost+found' with some small rests of something which > may be files in a previous life nothing was there... In that case its photorec time against the copy of the image (see previous note about only working on a copy - the changes that fsck makes may compromise photorec's efficacy). Probably worth reading the testdisk and photorec man pages first.
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
> Currently I am ddresucueing the flashcard to the harddisc. >>> Next I will try to mount the sdcard. >>> >>> I hope you meant to say "mount the sdcard image". Once ddrescue has done its best, you wont try to use the sdcard again. Also, you probably want to copy the image first, because when you try to fix it you will perform writes, and you dont want to lock yourself out of other recovery options by making potentially damaging writes. > What reliable sdcard-reader can one recommend ? >>> >> I'm not sure what you mean here given that you're making an image with ddrescue. Is the assumption correct, that -- if ddrescue could read each >> partitions of the sdcard without stuttering, retries and errors -- >> > the sdcard itsself is ok and "only" the logical structure >> (fs, superblock etc) got damaged? >> Or do I overlook something? >> > If ddrescue can read it cleanly with no retries (in which case it will offer no benefit over dd) then yes, I agree. However, given the cost of a card and the cost of your time and the risk to your data, I wouldnt be using it. > I dont know of a cdparanoia type recovery utility for sdcards but I > suspect sdcard design means that approach wont work. > I would just use photorec against a copy of the image. I have done this in the past and recovered many files from a ddrescued image of a failing USB drive, however, all the filenames were lost.
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 26/03/17 15:26, tu...@posteo.de wrote: On 03/26 03:04, Bill Kenworthy wrote: On 26/03/17 14:25, tu...@posteo.de wrote: On 03/26 05:50, tu...@posteo.de wrote: On 03/26 11:21, Adam Carter wrote: Step 1: dd the contents into an image ddrescue is probably a better option than plain dd. step 2: put the sdcard to one side. step 3: loopback mount a copy of the image (not the original) step 4: try recovering the filesystem on the loopback, if it fails ... try something else on another image copy Yep, once you've got the image mounted loopback, you can run testdisk/photorec depending on how bad it is. Hi all, thanks a lot for all help! :) Currently I am ddresucueing the flashcard to the harddisc. Next I will try to mount the sdcard. What reliable sdcard-reader can one recommend ? (...sorry if this sentence sounds harsh...I it by no means meant that way...I am no native speaker... :) Cheers Meino Hi, Is the assumption correct, that -- if ddrescue could read each partitions of the sdcard without stuttering, retries and errors -- the sdcard itsself is ok and "only" the logical structure (fs, superblock etc) got damaged? Or do I overlook something? (Background: I dont want to put a sdcard into the bin, if fdisking & reformatting that beast would gives me back an ok media...) Cheers Meino The dd gets you the best chance to work on the data before it completely fails. In my experience the sdcard will only get worse ending with total failure - if it hasn't already. If the dd dump comes up rubbish and cant be recovered, the actual sdcard will be worse. You can run "strings" against the image to see if there is any text in there (or even cat the /dev/sdcard node through strings) to see if the bits are still there. I dont know of a cdparanoia type recovery utility for sdcards but I suspect sdcard design means that approach wont work. BillK Hi Bill, I got mixed results: There are three partitions on the sdcard from which I could fully recover (even mount it directly via loop device) the first and the third one. The second one is screwed up. Running fsch.ext4 against the image it starts with "bad superblock" and suggests two alternatives. I started fsch.ext4 again while using -b to define the alternate superblock and it starts to ask me *zillions of question, which I all answered with 'yes' in a first attempt (I have a backup of the image...). The result was an image, which I could mount again. But beside 'lost+found' with some small rests of something which may be files in a previous life nothing was there Currently it looks to me, that something has totally messed up the fs there. What do you think? Cheers Meino Sounds like its toast :( I have never had a lot of luck with any of the ext file systems - you have to baby them and they corrupt very easily compared to others. I try and avoid them ... BillK
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 03/26 03:04, Bill Kenworthy wrote: > On 26/03/17 14:25, tu...@posteo.de wrote: > > On 03/26 05:50, tu...@posteo.de wrote: > > > On 03/26 11:21, Adam Carter wrote: > > > > Step 1: dd the contents into an image > > > > > > > > ddrescue is probably a better option than plain dd. > > > > > > > > step 2: put the sdcard to one side. > > > > > step 3: loopback mount a copy of the image (not the original) > > > > > step 4: try recovering the filesystem on the loopback, if it fails > > > > > ... try > > > > > something else on another image copy > > > > > > > > > > > > Yep, once you've got the image mounted loopback, you can run > > > > testdisk/photorec depending on how bad it is. > > > > > > Hi all, > > > > > > thanks a lot for all help! :) > > > > > > Currently I am ddresucueing the flashcard to the harddisc. > > > Next I will try to mount the sdcard. > > > > > > What reliable sdcard-reader can one recommend ? > > > (...sorry if this sentence sounds harsh...I it by no means meant > > > that way...I am no native speaker... :) > > > > > > Cheers > > > Meino > > > > > > > > > > Hi, > > > > Is the assumption correct, that -- if ddrescue could read each > > partitions of the sdcard without stuttering, retries and errors -- > > the sdcard itsself is ok and "only" the logical structure > > (fs, superblock etc) got damaged? > > Or do I overlook something? > > > > (Background: I dont want to put a sdcard into the bin, if > > fdisking & reformatting that beast would gives me back an ok > > media...) > > > > Cheers > > Meino > > > > > > > > > > The dd gets you the best chance to work on the data before it completely > fails. In my experience the sdcard will only get worse ending with total > failure - if it hasn't already. > > If the dd dump comes up rubbish and cant be recovered, the actual sdcard > will be worse. You can run "strings" against the image to see if there is > any text in there (or even cat the /dev/sdcard node through strings) to see > if the bits are still there. > > I dont know of a cdparanoia type recovery utility for sdcards but I suspect > sdcard design means that approach wont work. > > BillK > > > Hi Bill, I got mixed results: There are three partitions on the sdcard from which I could fully recover (even mount it directly via loop device) the first and the third one. The second one is screwed up. Running fsch.ext4 against the image it starts with "bad superblock" and suggests two alternatives. I started fsch.ext4 again while using -b to define the alternate superblock and it starts to ask me *zillions of question, which I all answered with 'yes' in a first attempt (I have a backup of the image...). The result was an image, which I could mount again. But beside 'lost+found' with some small rests of something which may be files in a previous life nothing was there Currently it looks to me, that something has totally messed up the fs there. What do you think? Cheers Meino
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 26/03/17 14:25, tu...@posteo.de wrote: On 03/26 05:50, tu...@posteo.de wrote: On 03/26 11:21, Adam Carter wrote: Step 1: dd the contents into an image ddrescue is probably a better option than plain dd. step 2: put the sdcard to one side. step 3: loopback mount a copy of the image (not the original) step 4: try recovering the filesystem on the loopback, if it fails ... try something else on another image copy Yep, once you've got the image mounted loopback, you can run testdisk/photorec depending on how bad it is. Hi all, thanks a lot for all help! :) Currently I am ddresucueing the flashcard to the harddisc. Next I will try to mount the sdcard. What reliable sdcard-reader can one recommend ? (...sorry if this sentence sounds harsh...I it by no means meant that way...I am no native speaker... :) Cheers Meino Hi, Is the assumption correct, that -- if ddrescue could read each partitions of the sdcard without stuttering, retries and errors -- the sdcard itsself is ok and "only" the logical structure (fs, superblock etc) got damaged? Or do I overlook something? (Background: I dont want to put a sdcard into the bin, if fdisking & reformatting that beast would gives me back an ok media...) Cheers Meino The dd gets you the best chance to work on the data before it completely fails. In my experience the sdcard will only get worse ending with total failure - if it hasn't already. If the dd dump comes up rubbish and cant be recovered, the actual sdcard will be worse. You can run "strings" against the image to see if there is any text in there (or even cat the /dev/sdcard node through strings) to see if the bits are still there. I dont know of a cdparanoia type recovery utility for sdcards but I suspect sdcard design means that approach wont work. BillK
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 03/26 05:50, tu...@posteo.de wrote: > On 03/26 11:21, Adam Carter wrote: > > Step 1: dd the contents into an image > > > > ddrescue is probably a better option than plain dd. > > > > step 2: put the sdcard to one side. > > > step 3: loopback mount a copy of the image (not the original) > > > step 4: try recovering the filesystem on the loopback, if it fails ... try > > > something else on another image copy > > > > > > Yep, once you've got the image mounted loopback, you can run > > testdisk/photorec depending on how bad it is. > > Hi all, > > thanks a lot for all help! :) > > Currently I am ddresucueing the flashcard to the harddisc. > Next I will try to mount the sdcard. > > What reliable sdcard-reader can one recommend ? > (...sorry if this sentence sounds harsh...I it by no means meant > that way...I am no native speaker... :) > > Cheers > Meino > > Hi, Is the assumption correct, that -- if ddrescue could read each partitions of the sdcard without stuttering, retries and errors -- the sdcard itsself is ok and "only" the logical structure (fs, superblock etc) got damaged? Or do I overlook something? (Background: I dont want to put a sdcard into the bin, if fdisking & reformatting that beast would gives me back an ok media...) Cheers Meino
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 03/26 11:21, Adam Carter wrote: > Step 1: dd the contents into an image > > ddrescue is probably a better option than plain dd. > > step 2: put the sdcard to one side. > > step 3: loopback mount a copy of the image (not the original) > > step 4: try recovering the filesystem on the loopback, if it fails ... try > > something else on another image copy > > > Yep, once you've got the image mounted loopback, you can run > testdisk/photorec depending on how bad it is. Hi all, thanks a lot for all help! :) Currently I am ddresucueing the flashcard to the harddisc. Next I will try to mount the sdcard. What reliable sdcard-reader can one recommend ? (...sorry if this sentence sounds harsh...I it by no means meant that way...I am no native speaker... :) Cheers Meino
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
Step 1: dd the contents into an image ddrescue is probably a better option than plain dd. step 2: put the sdcard to one side. > step 3: loopback mount a copy of the image (not the original) > step 4: try recovering the filesystem on the loopback, if it fails ... try > something else on another image copy Yep, once you've got the image mounted loopback, you can run testdisk/photorec depending on how bad it is.
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 26/03/17 03:15, tu...@posteo.de wrote: Hi, (Running Gentoo Linux on a 4.9.17 vanilla (ftp.kernel.org) Linux kernel) I was doing a backyp of a 64GB SAMSUNG flash card to my harddiskwhich runs for quite a while... For that I mount the partitions and tarred their contents as root to the harddisk Syddenly out of nothing/from nowhere/into thin air or whatever: read errors happens and the process stops. Step 1: dd the contents into an image step 2: put the sdcard to one side. step 3: loopback mount a copy of the image (not the original) step 4: try recovering the filesystem on the loopback, if it fails ... try something else on another image copy. SDcard reliability sucks :( William K.
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
tu...@posteo.de wrote: > Hi, > > (Running Gentoo Linux on a 4.9.17 vanilla (ftp.kernel.org) Linux > kernel) > > I was doing a backyp of a 64GB SAMSUNG flash card to my > harddiskwhich runs for quite a while... > > For that I mount the partitions and tarred their contents as root > to the harddisk > > Syddenly out of nothing/from nowhere/into thin air or whatever: > read errors happens and the process stops. > > First I thought of the one an most hated failure of harddisks, which > in years of deveopment of computer technology no company was able to > fix: No space left on device. > > But - no,,,the error was a _READ_ error and a 'ls' of the mountpoints > shownothing but empty directories. > > I tried to unmount/remount the sd card and got this output: > mount: wrong fs type, bad option, bad superblock on /dev/sdb2, >missing codepage or helper program, or other error > >In some cases useful info is found in syslog - try >dmesg | tail or so. > > dmesg gives me: > [ 236.021878] UDF-fs: warning (device sdb2): udf_fill_super: No > partition found (2) > > > UDF??? -- Those partitions are either ext4 or vfat. > (A tried that with and without the -t option...) > > fdisk -l /dev/sdb gave me: > Device Boot Start End Sectors Size Id Type > /dev/sdb1 32768 73433087 73400320 35G 83 Linux > /dev/sdb273433088 100696063 27262976 13G 83 Linux > /dev/sdb3 100696064 125042687 24346624 11.6G 83 Linux > > So -- the partition table is still there (I had booted the PC > in between...so these are no ghosts of an abondomed cache...) > > If a certain kernel module woyld be missing I wouldn't not > able to mount the partition right before starting the backyp > - but I could. > > The partition table is there so this part of "DMESG predicts" > is also not applicable here. > > What happens here? Flash killed? Is there any chance to rescye > some or all contents of that card? Any ideas other than > hoping for an alternate reality? You can try to recover some data with photorec (part of testdisk). Btw.: If it is a microsd card I would put it into an microsd-to-sd adapter. I made some strange experiences with different types of card readers when I used microsd cards directly without an adapter. -- Regards wabe
Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
On 03/25/2017 12:15 PM, tu...@posteo.de wrote: > What happens here? Flash killed? Is there any chance to rescye > some or all contents of that card? Any ideas other than > hoping for an alternate reality? Sounds to me like your card is dead. I've had this happen to several SSDs too by the way, they fail the same way. One minute it works, the next it's dead. It's why I don't keep anything valuable on SSDs. They're way too unpredictable for my tastes. Dan
