Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
Eddie G. O'Connor Jr. wrote: On 09/23/2012 07:22 PM, Roger wrote: On 09/24/2012 02:09 AM, Eddie G. O'Connor Jr. wrote: On 09/23/2012 07:33 AM, Jakub Kicinski wrote: Hi all, I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. But first: 1. The rant Clearly something bad is going on in Fedora world. I've been upgrading to Alphas/Betas for years now and it never caused more trouble than occasional need to rebuild some packages manually. I read this: http://lwn.net/Articles/506831/ but I didn't suspect that not only Rawhide, but also Alpha releases became unusable. First of all PreUpgrade crashes before it starts. I thought, well, I'll try DVD. It kind of worked. I was looking for words like upgrade or update in the new and shiny anaconda but no luck. Eventually it started the installation (without any Warning: write changes to disk? or alike). At that point partitions of Fedora 17 where already magically renamed to Fedora 18, so I hoped for the best. Unfortunately anaconda crashed when it tried to format my Win7 partition to the widely used filesystem None?! Imagine my amusement when after reboot I realised that MBR and GPT where wiped out and all of my partitions were nowhere to be found. 2. The problem It turned out anaconda not only wipes out MBR but also removes magic numbers from partitions superblocks (anyone can explain why?). So the good news was my data was still there, the bad news was: none of automatic lost partition detection tool could find them (at least none that I know of). 3. The solution If it happens to you as well, here is what you can try to get your data back: a. Accept that you do all this on your own risk ;) b. Backup your HDD, preferably all of it. Backup can be done with dd. c. Connect damaged HDD to some other Linux box or use a Live distribution. d. Now you need to locate your first partition. There is a good chance that this will be your /boot and Fedora usually locates it at 0x10 (i.e. it starts in 2048 sector). Other possibility is sector 63/64 from pre-GPT world. e. Set magic value in superblock (see below). f. Try mounting partition using offset option in mount. g. Calculate where next partition is most likely to start using block count and block size from superblock. h. Fix your MBR. You can probably do that in parted or some similar tool, but who would trust tools after one just nearly destroyed all your data. i. If you have more partitions to find, go back to (d). Important: All values on disk are LITTLE ENDIAN. Important: Try mounting your partitions read-only first. Notes on EXT4. Ext4 is quite easy to find. You will recognize it by two zeroed out sectors (1024 bytes of zeroes) at the beginning of every partition. NOTE: those zeroes are *in* the partition, do not skip them when trying to mount. After zeroes there is a superblock. What you are looking for is offset +0x38 in the superblock, where you once had a magic value of 0xEF53, you will probably have to put it back there. More information on EXT4: https://ext4.wiki.kernel.org/index.php/Ext4_Disk_Layout Notes on NTFS. NTFS partition starts with EB 52 90, there are no zeroes in front. Magic value which is removed by anaconda is 4E 54 46 53 20 20 20 20 at offset 0x03 into a partition. Its literally NTFS (with spaces). More info: http://technet.microsoft.com/en-us/library/cc781134%28v=ws.10%29.aspx Useful tools: dd - will help you to copy blocks of data around. If you don't know it already, I advise you to read some tutorial and practise first. It's easy to destroy thing with one wrong dd. emacs, okteta etc. - hex editor... losetup - is a tool which enables you to mount files and drives at particular offset as loop devices. Very useful, read more here: http://rackerhacker.com/2010/12/14/mounting-a-raw-partition-file-made-with-dd-or-dd_rescue-in-linux/ dumpe2fs, nftsinfo - will decode superblock for you. bash calculator - $((1+2+3+4*4)) can save you a lot of time. bash printf - printf %d\n 0x1AB2F or printf %x\n $((7863*4096)) is handy as well. Good luck from (a sightly less happy) Fedora user -- Kuba WOW!.that's terrible! But I guess that's just one of the reasons I purposely wait until a release has been out for almost 3 monthsbefore installing / upgrading. It just makes it a little easier when the glitches have been made apparent and are either completely worked out or are in the process of being worked out. In all honesty...I actually prefer to wait a few releases before upgrading, I kind of have my OWN schedule I usually wait and let one release pass by, then I'll wait for the next version...and 3 to 4 months into _that _I'll upgrade.this helps me remain a little more stable and not have to scurry around upgrading every 6 months EGO II Yes I am much the same. I'll skip an upgrade or two, wait for stability then after copying all my
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
Eddie G. O'Connor Jr. wrote: On 09/23/2012 07:33 AM, Jakub Kicinski wrote: Hi all, I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. But first: 1. The rant Clearly something bad is going on in Fedora world. I've been upgrading to Alphas/Betas for years now and it never caused more trouble than occasional need to rebuild some packages manually. I read this: http://lwn.net/Articles/506831/ but I didn't suspect that not only Rawhide, but also Alpha releases became unusable. First of all PreUpgrade crashes before it starts. I thought, well, I'll try DVD. It kind of worked. I was looking for words like upgrade or update in the new and shiny anaconda but no luck. Eventually it started the installation (without any Warning: write changes to disk? or alike). At that point partitions of Fedora 17 where already magically renamed to Fedora 18, so I hoped for the best. Unfortunately anaconda crashed when it tried to format my Win7 partition to the widely used filesystem None?! Imagine my amusement when after reboot I realised that MBR and GPT where wiped out and all of my partitions were nowhere to be found. 2. The problem It turned out anaconda not only wipes out MBR but also removes magic numbers from partitions superblocks (anyone can explain why?). So the good news was my data was still there, the bad news was: none of automatic lost partition detection tool could find them (at least none that I know of). 3. The solution If it happens to you as well, here is what you can try to get your data back: a. Accept that you do all this on your own risk ;) b. Backup your HDD, preferably all of it. Backup can be done with dd. c. Connect damaged HDD to some other Linux box or use a Live distribution. d. Now you need to locate your first partition. There is a good chance that this will be your /boot and Fedora usually locates it at 0x10 (i.e. it starts in 2048 sector). Other possibility is sector 63/64 from pre-GPT world. e. Set magic value in superblock (see below). f. Try mounting partition using offset option in mount. g. Calculate where next partition is most likely to start using block count and block size from superblock. h. Fix your MBR. You can probably do that in parted or some similar tool, but who would trust tools after one just nearly destroyed all your data. i. If you have more partitions to find, go back to (d). Important: All values on disk are LITTLE ENDIAN. Important: Try mounting your partitions read-only first. Notes on EXT4. Ext4 is quite easy to find. You will recognize it by two zeroed out sectors (1024 bytes of zeroes) at the beginning of every partition. NOTE: those zeroes are *in* the partition, do not skip them when trying to mount. After zeroes there is a superblock. What you are looking for is offset +0x38 in the superblock, where you once had a magic value of 0xEF53, you will probably have to put it back there. More information on EXT4: https://ext4.wiki.kernel.org/index.php/Ext4_Disk_Layout Notes on NTFS. NTFS partition starts with EB 52 90, there are no zeroes in front. Magic value which is removed by anaconda is 4E 54 46 53 20 20 20 20 at offset 0x03 into a partition. Its literally NTFS (with spaces). More info: http://technet.microsoft.com/en-us/library/cc781134%28v=ws.10%29.aspx Useful tools: dd - will help you to copy blocks of data around. If you don't know it already, I advise you to read some tutorial and practise first. It's easy to destroy thing with one wrong dd. emacs, okteta etc. - hex editor... losetup - is a tool which enables you to mount files and drives at particular offset as loop devices. Very useful, read more here: http://rackerhacker.com/2010/12/14/mounting-a-raw-partition-file-made-with-dd-or-dd_rescue-in-linux/ dumpe2fs, nftsinfo - will decode superblock for you. bash calculator - $((1+2+3+4*4)) can save you a lot of time. bash printf - printf %d\n 0x1AB2F or printf %x\n $((7863*4096)) is handy as well. Good luck from (a sightly less happy) Fedora user -- Kuba WOW!.that's terrible! But I guess that's just one of the reasons I purposely wait until a release has been out for almost 3 monthsbefore installing / upgrading. It just makes it a little easier when the glitches have been made apparent and are either completely worked out or are in the process of being worked out. In all honesty...I actually prefer to wait a few releases before upgrading, I kind of have my OWN schedule I usually wait and let one release pass by, then I'll wait for the next version...and 3 to 4 months into _that _I'll upgrade.this helps me remain a little more stable and not have to scurry around upgrading every 6 months I followed FC from 4-6-9-13-16-17, generally updating when a security issue popped up I didn't want to patch myself. The 16-17 was because of the kernel, too much good stuff added to miss on my VM
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On Tue, 2012-09-25 at 01:31 +0100, Ian Malone wrote: On 25 September 2012 00:55, Joe Zeff j...@zeff.us wrote: On 09/24/2012 04:44 PM, Jakub Kicinski wrote: On Mon, 24 Sep 2012 08:09:11 -0430, Patrick O'Callaghan pocallag...@gmail.com wrote: On Sun, 2012-09-23 at 13:33 +0200, Jakub Kicinski wrote: I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. This should be posted to the Fedora test list, not here. F18 is not a released system. Sorry, won't happen again. Please don't think you've offended us, Kuba, or that we want you to go away and stay there. It's just that in this case, you asked a question that we're really not qualified to answer, so Patrick pointed you in the right direction. And, there's no reason to sign off of the list if you haven't already done so. It won't be too long before F18 has its coming out party, making it very appropriate for this list. Actually, I think it's worth having this mentioned on this list. The problem (F18 alpha will eat your data) is fairly well known on the devel list, but the fact that Jakub thought this needed a post suggests that people on the users list aren't aware of it at a time at which they might start trying Alpha. So starting a 'here be dragons' thread is not completely unwarranted. (Also a bit extreme to say we absolutely cannot mention F18 here when the assumption on devel is often that you are a maintainer or developer, this is the users list after all.) None of these lists have rigid rules, but they do have community guidelines. Keeping discussion of unreleased development versions to the Test list is a sensible example. My take on Jakub's post is that he was unaware of the Test list until it was pointed out to him. Someone who's going to be trying out F18 at this stage (it's still months from release) really needs to get on the list that's specifically for devels *and testers* or they're going to have a frustrating time of it. poc -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On 24/09/12 00:43, Eddie G. O'Connor Jr. wrote: It just seems that.of all the different methodsTHAT one is the safest. I've accumulated quite a few irreplaceable files throughout the years...and I'd hate to lose some or all of them due to a restructuring of the build for the installer!.. External drive(s) may be a safer place to keep irreplacable files. I use a simple Raid1 NAS for must keep files. -- Regards, Frank Jack of all, fubars -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On 09/24/2012 03:55 AM, Frank Murphy wrote: On 24/09/12 00:43, Eddie G. O'Connor Jr. wrote: It just seems that.of all the different methodsTHAT one is the safest. I've accumulated quite a few irreplaceable files throughout the years...and I'd hate to lose some or all of them due to a restructuring of the build for the installer!.. External drive(s) may be a safer place to keep irreplacable files. I use a simple Raid1 NAS for must keep files. Oh I agree TOTALLY! Although I have like over a thousand files that are directly stored on my PC I ALSO have them stored on a 1TB drive in an encrypted folder, so should anything ever happen, I can put back what's lost or corrupted. Also I run the Backup tool every month, with incremental backups between the monthly ones. I do NOT intend on losing data EVER again! The last time I DID lose data was when I was going from Windows to Linux, and ever since losing some very vintage guitar sounds from my Cakewalk days, I've never done ANYTHING without a backup made first. On a totally different note, but related just the same...because of all the files I have now I'm thinking maybe it's time for a dedicated server to hold them all, can someone recommend an OS/distro that would handle this along with possible printer duties and security that will be easy to use and light on the hardware?(and just FYI I have no command line/scripting skills so something with a GUI would be preferred!...) EGO II -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On Sun, 2012-09-23 at 13:33 +0200, Jakub Kicinski wrote: I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. This should be posted to the Fedora test list, not here. F18 is not a released system. poc -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 09/24/2012 07:39 AM, Patrick O'Callaghan wrote: On Sun, 2012-09-23 at 13:33 +0200, Jakub Kicinski wrote: I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. This should be posted to the Fedora test list, not here. F18 is not a released system. poc One program I did not see talked about is testdisk. It is designed to find deleted partitions. I have not needed to use it for real, but I have deliberately messed up a partition table to see how well it works. It does a great job on drives that have only been partitioned and formatted once. If you have had different partitioning sachems, you may have to pick out the correct partitions from a list of partitions it finds. But it usually isn't too hard. Mikkel - -- Do not meddle in the affairs of dragons, for thou art crunchy and taste good with Ketchup! -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlBgYegACgkQqbQrVW3JyMQAYgCfZUpeQ1WZ1oxr/GD6O7Q5p7n/ GDYAnRY3jzhT34idR6/UFH3pM5GsHBMo =0ClG -END PGP SIGNATURE- -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On Mon, 24 Sep 2012 08:36:41 -0500, Mikkel L. Ellertson mellert...@gmail.com wrote: On 09/24/2012 07:39 AM, Patrick O'Callaghan wrote: On Sun, 2012-09-23 at 13:33 +0200, Jakub Kicinski wrote: I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. This should be posted to the Fedora test list, not here. F18 is not a released system. poc One program I did not see talked about is testdisk. It is designed to find deleted partitions. I have not needed to use it for real, but I have deliberately messed up a partition table to see how well it works. It does a great job on drives that have only been partitioned and formatted once. If you have had different partitioning sachems, you may have to pick out the correct partitions from a list of partitions it finds. But it usually isn't too hard. Well I didn't mention it because I said: anaconda [...] removes magic numbers from partitions superblocks [...] and none of automatic lost partition detection tool could find them. I tried testdisk with a few different settings, none of them worked. Only partition it was kind of able to detect was the first on (/boot) and even there it messed up starting point (2046 instead of 2048 sector). But yes, nevertheless, if someone just wipes out his MBR testdisk would be very useful I agree. -- Kuba -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On Mon, 24 Sep 2012 08:09:11 -0430, Patrick O'Callaghan pocallag...@gmail.com wrote: On Sun, 2012-09-23 at 13:33 +0200, Jakub Kicinski wrote: I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. This should be posted to the Fedora test list, not here. F18 is not a released system. Sorry, won't happen again. -- Kuba -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On 09/24/2012 04:44 PM, Jakub Kicinski wrote: On Mon, 24 Sep 2012 08:09:11 -0430, Patrick O'Callaghan pocallag...@gmail.com wrote: On Sun, 2012-09-23 at 13:33 +0200, Jakub Kicinski wrote: I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. This should be posted to the Fedora test list, not here. F18 is not a released system. Sorry, won't happen again. Please don't think you've offended us, Kuba, or that we want you to go away and stay there. It's just that in this case, you asked a question that we're really not qualified to answer, so Patrick pointed you in the right direction. And, there's no reason to sign off of the list if you haven't already done so. It won't be too long before F18 has its coming out party, making it very appropriate for this list. -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On 25 September 2012 00:55, Joe Zeff j...@zeff.us wrote: On 09/24/2012 04:44 PM, Jakub Kicinski wrote: On Mon, 24 Sep 2012 08:09:11 -0430, Patrick O'Callaghan pocallag...@gmail.com wrote: On Sun, 2012-09-23 at 13:33 +0200, Jakub Kicinski wrote: I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. This should be posted to the Fedora test list, not here. F18 is not a released system. Sorry, won't happen again. Please don't think you've offended us, Kuba, or that we want you to go away and stay there. It's just that in this case, you asked a question that we're really not qualified to answer, so Patrick pointed you in the right direction. And, there's no reason to sign off of the list if you haven't already done so. It won't be too long before F18 has its coming out party, making it very appropriate for this list. Actually, I think it's worth having this mentioned on this list. The problem (F18 alpha will eat your data) is fairly well known on the devel list, but the fact that Jakub thought this needed a post suggests that people on the users list aren't aware of it at a time at which they might start trying Alpha. So starting a 'here be dragons' thread is not completely unwarranted. (Also a bit extreme to say we absolutely cannot mention F18 here when the assumption on devel is often that you are a maintainer or developer, this is the users list after all.) -- imalone http://ibmalone.blogspot.co.uk -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On 09/23/2012 01:33 PM, Jakub Kicinski wrote: I realised that MBR and GPT where wiped out and all of my partitions were nowhere to be found. A useful habit to have: fdisk -l /dev/sd? save_this_file_away__it_could_be_important_some_day.txt -- Roberto Ragusamail at robertoragusa.it -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On 09/23/2012 07:33 AM, Jakub Kicinski wrote: Hi all, I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. But first: 1. The rant Clearly something bad is going on in Fedora world. I've been upgrading to Alphas/Betas for years now and it never caused more trouble than occasional need to rebuild some packages manually. I read this: http://lwn.net/Articles/506831/ but I didn't suspect that not only Rawhide, but also Alpha releases became unusable. First of all PreUpgrade crashes before it starts. I thought, well, I'll try DVD. It kind of worked. I was looking for words like upgrade or update in the new and shiny anaconda but no luck. Eventually it started the installation (without any Warning: write changes to disk? or alike). At that point partitions of Fedora 17 where already magically renamed to Fedora 18, so I hoped for the best. Unfortunately anaconda crashed when it tried to format my Win7 partition to the widely used filesystem None?! Imagine my amusement when after reboot I realised that MBR and GPT where wiped out and all of my partitions were nowhere to be found. 2. The problem It turned out anaconda not only wipes out MBR but also removes magic numbers from partitions superblocks (anyone can explain why?). So the good news was my data was still there, the bad news was: none of automatic lost partition detection tool could find them (at least none that I know of). 3. The solution If it happens to you as well, here is what you can try to get your data back: a. Accept that you do all this on your own risk ;) b. Backup your HDD, preferably all of it. Backup can be done with dd. c. Connect damaged HDD to some other Linux box or use a Live distribution. d. Now you need to locate your first partition. There is a good chance that this will be your /boot and Fedora usually locates it at 0x10 (i.e. it starts in 2048 sector). Other possibility is sector 63/64 from pre-GPT world. e. Set magic value in superblock (see below). f. Try mounting partition using offset option in mount. g. Calculate where next partition is most likely to start using block count and block size from superblock. h. Fix your MBR. You can probably do that in parted or some similar tool, but who would trust tools after one just nearly destroyed all your data. i. If you have more partitions to find, go back to (d). Important: All values on disk are LITTLE ENDIAN. Important: Try mounting your partitions read-only first. Notes on EXT4. Ext4 is quite easy to find. You will recognize it by two zeroed out sectors (1024 bytes of zeroes) at the beginning of every partition. NOTE: those zeroes are *in* the partition, do not skip them when trying to mount. After zeroes there is a superblock. What you are looking for is offset +0x38 in the superblock, where you once had a magic value of 0xEF53, you will probably have to put it back there. More information on EXT4: https://ext4.wiki.kernel.org/index.php/Ext4_Disk_Layout Notes on NTFS. NTFS partition starts with EB 52 90, there are no zeroes in front. Magic value which is removed by anaconda is 4E 54 46 53 20 20 20 20 at offset 0x03 into a partition. Its literally NTFS (with spaces). More info: http://technet.microsoft.com/en-us/library/cc781134%28v=ws.10%29.aspx Useful tools: dd - will help you to copy blocks of data around. If you don't know it already, I advise you to read some tutorial and practise first. It's easy to destroy thing with one wrong dd. emacs, okteta etc. - hex editor... losetup - is a tool which enables you to mount files and drives at particular offset as loop devices. Very useful, read more here: http://rackerhacker.com/2010/12/14/mounting-a-raw-partition-file-made-with-dd-or-dd_rescue-in-linux/ dumpe2fs, nftsinfo - will decode superblock for you. bash calculator - $((1+2+3+4*4)) can save you a lot of time. bash printf - printf %d\n 0x1AB2F or printf %x\n $((7863*4096)) is handy as well. Good luck from (a sightly less happy) Fedora user -- Kuba WOW!.that's terrible! But I guess that's just one of the reasons I purposely wait until a release has been out for almost 3 monthsbefore installing / upgrading. It just makes it a little easier when the glitches have been made apparent and are either completely worked out or are in the process of being worked out. In all honesty...I actually prefer to wait a few releases before upgrading, I kind of have my OWN schedule I usually wait and let one release pass by, then I'll wait for the next version...and 3 to 4 months into _that _I'll upgrade.this helps me remain a little more stable and not have to scurry around upgrading every 6 months EGO II -- users mailing list users@lists.fedoraproject.org To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines:
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On 09/24/2012 02:09 AM, Eddie G. O'Connor Jr. wrote: On 09/23/2012 07:33 AM, Jakub Kicinski wrote: Hi all, I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. But first: 1. The rant Clearly something bad is going on in Fedora world. I've been upgrading to Alphas/Betas for years now and it never caused more trouble than occasional need to rebuild some packages manually. I read this: http://lwn.net/Articles/506831/ but I didn't suspect that not only Rawhide, but also Alpha releases became unusable. First of all PreUpgrade crashes before it starts. I thought, well, I'll try DVD. It kind of worked. I was looking for words like upgrade or update in the new and shiny anaconda but no luck. Eventually it started the installation (without any Warning: write changes to disk? or alike). At that point partitions of Fedora 17 where already magically renamed to Fedora 18, so I hoped for the best. Unfortunately anaconda crashed when it tried to format my Win7 partition to the widely used filesystem None?! Imagine my amusement when after reboot I realised that MBR and GPT where wiped out and all of my partitions were nowhere to be found. 2. The problem It turned out anaconda not only wipes out MBR but also removes magic numbers from partitions superblocks (anyone can explain why?). So the good news was my data was still there, the bad news was: none of automatic lost partition detection tool could find them (at least none that I know of). 3. The solution If it happens to you as well, here is what you can try to get your data back: a. Accept that you do all this on your own risk ;) b. Backup your HDD, preferably all of it. Backup can be done with dd. c. Connect damaged HDD to some other Linux box or use a Live distribution. d. Now you need to locate your first partition. There is a good chance that this will be your /boot and Fedora usually locates it at 0x10 (i.e. it starts in 2048 sector). Other possibility is sector 63/64 from pre-GPT world. e. Set magic value in superblock (see below). f. Try mounting partition using offset option in mount. g. Calculate where next partition is most likely to start using block count and block size from superblock. h. Fix your MBR. You can probably do that in parted or some similar tool, but who would trust tools after one just nearly destroyed all your data. i. If you have more partitions to find, go back to (d). Important: All values on disk are LITTLE ENDIAN. Important: Try mounting your partitions read-only first. Notes on EXT4. Ext4 is quite easy to find. You will recognize it by two zeroed out sectors (1024 bytes of zeroes) at the beginning of every partition. NOTE: those zeroes are *in* the partition, do not skip them when trying to mount. After zeroes there is a superblock. What you are looking for is offset +0x38 in the superblock, where you once had a magic value of 0xEF53, you will probably have to put it back there. More information on EXT4: https://ext4.wiki.kernel.org/index.php/Ext4_Disk_Layout Notes on NTFS. NTFS partition starts with EB 52 90, there are no zeroes in front. Magic value which is removed by anaconda is 4E 54 46 53 20 20 20 20 at offset 0x03 into a partition. Its literally NTFS (with spaces). More info: http://technet.microsoft.com/en-us/library/cc781134%28v=ws.10%29.aspx Useful tools: dd - will help you to copy blocks of data around. If you don't know it already, I advise you to read some tutorial and practise first. It's easy to destroy thing with one wrong dd. emacs, okteta etc. - hex editor... losetup - is a tool which enables you to mount files and drives at particular offset as loop devices. Very useful, read more here: http://rackerhacker.com/2010/12/14/mounting-a-raw-partition-file-made-with-dd-or-dd_rescue-in-linux/ dumpe2fs, nftsinfo - will decode superblock for you. bash calculator - $((1+2+3+4*4)) can save you a lot of time. bash printf - printf %d\n 0x1AB2F or printf %x\n $((7863*4096)) is handy as well. Good luck from (a sightly less happy) Fedora user -- Kuba WOW!.that's terrible! But I guess that's just one of the reasons I purposely wait until a release has been out for almost 3 monthsbefore installing / upgrading. It just makes it a little easier when the glitches have been made apparent and are either completely worked out or are in the process of being worked out. In all honesty...I actually prefer to wait a few releases before upgrading, I kind of have my OWN schedule I usually wait and let one release pass by, then I'll wait for the next version...and 3 to 4 months into _that _I'll upgrade.this helps me remain a little more stable and not have to scurry around upgrading every 6 months EGO II Yes I am much the same. I'll skip an upgrade or two, wait for stability then after copying all my files, do a fresh install. Roger -- users mailing list
Re: How to rescue your partitions after upgrade to Fedora 18 Alpha eats them
On 09/23/2012 07:22 PM, Roger wrote: On 09/24/2012 02:09 AM, Eddie G. O'Connor Jr. wrote: On 09/23/2012 07:33 AM, Jakub Kicinski wrote: Hi all, I recently had a weird problem after upgrade to Fedora 18 Alpha. I decided to share the solution, maybe it will help someone. But first: 1. The rant Clearly something bad is going on in Fedora world. I've been upgrading to Alphas/Betas for years now and it never caused more trouble than occasional need to rebuild some packages manually. I read this: http://lwn.net/Articles/506831/ but I didn't suspect that not only Rawhide, but also Alpha releases became unusable. First of all PreUpgrade crashes before it starts. I thought, well, I'll try DVD. It kind of worked. I was looking for words like upgrade or update in the new and shiny anaconda but no luck. Eventually it started the installation (without any Warning: write changes to disk? or alike). At that point partitions of Fedora 17 where already magically renamed to Fedora 18, so I hoped for the best. Unfortunately anaconda crashed when it tried to format my Win7 partition to the widely used filesystem None?! Imagine my amusement when after reboot I realised that MBR and GPT where wiped out and all of my partitions were nowhere to be found. 2. The problem It turned out anaconda not only wipes out MBR but also removes magic numbers from partitions superblocks (anyone can explain why?). So the good news was my data was still there, the bad news was: none of automatic lost partition detection tool could find them (at least none that I know of). 3. The solution If it happens to you as well, here is what you can try to get your data back: a. Accept that you do all this on your own risk ;) b. Backup your HDD, preferably all of it. Backup can be done with dd. c. Connect damaged HDD to some other Linux box or use a Live distribution. d. Now you need to locate your first partition. There is a good chance that this will be your /boot and Fedora usually locates it at 0x10 (i.e. it starts in 2048 sector). Other possibility is sector 63/64 from pre-GPT world. e. Set magic value in superblock (see below). f. Try mounting partition using offset option in mount. g. Calculate where next partition is most likely to start using block count and block size from superblock. h. Fix your MBR. You can probably do that in parted or some similar tool, but who would trust tools after one just nearly destroyed all your data. i. If you have more partitions to find, go back to (d). Important: All values on disk are LITTLE ENDIAN. Important: Try mounting your partitions read-only first. Notes on EXT4. Ext4 is quite easy to find. You will recognize it by two zeroed out sectors (1024 bytes of zeroes) at the beginning of every partition. NOTE: those zeroes are *in* the partition, do not skip them when trying to mount. After zeroes there is a superblock. What you are looking for is offset +0x38 in the superblock, where you once had a magic value of 0xEF53, you will probably have to put it back there. More information on EXT4: https://ext4.wiki.kernel.org/index.php/Ext4_Disk_Layout Notes on NTFS. NTFS partition starts with EB 52 90, there are no zeroes in front. Magic value which is removed by anaconda is 4E 54 46 53 20 20 20 20 at offset 0x03 into a partition. Its literally NTFS (with spaces). More info: http://technet.microsoft.com/en-us/library/cc781134%28v=ws.10%29.aspx Useful tools: dd - will help you to copy blocks of data around. If you don't know it already, I advise you to read some tutorial and practise first. It's easy to destroy thing with one wrong dd. emacs, okteta etc. - hex editor... losetup - is a tool which enables you to mount files and drives at particular offset as loop devices. Very useful, read more here: http://rackerhacker.com/2010/12/14/mounting-a-raw-partition-file-made-with-dd-or-dd_rescue-in-linux/ dumpe2fs, nftsinfo - will decode superblock for you. bash calculator - $((1+2+3+4*4)) can save you a lot of time. bash printf - printf %d\n 0x1AB2F or printf %x\n $((7863*4096)) is handy as well. Good luck from (a sightly less happy) Fedora user -- Kuba WOW!.that's terrible! But I guess that's just one of the reasons I purposely wait until a release has been out for almost 3 monthsbefore installing / upgrading. It just makes it a little easier when the glitches have been made apparent and are either completely worked out or are in the process of being worked out. In all honesty...I actually prefer to wait a few releases before upgrading, I kind of have my OWN schedule I usually wait and let one release pass by, then I'll wait for the next version...and 3 to 4 months into _that _I'll upgrade.this helps me remain a little more stable and not have to scurry around upgrading every 6 months EGO II Yes I am much the same. I'll skip an upgrade or two, wait for stability then after copying all my files, do a fresh
