* [Qemu-devel] qemu 2.9.0 qcow2 file failed to open after hard server reset
@ 2017-12-21 22:13 Vasiliy Tolstov
2017-12-21 22:58 ` John Snow
0 siblings, 1 reply; 6+ messages in thread
From: Vasiliy Tolstov @ 2017-12-21 22:13 UTC (permalink / raw)
To: qemu-devel
Hi! Today my server have forced reboot and one of my vm can't start
with message:
qcow2: Marking image as corrupt: L2 table offset 0x3f786d6c207600
unaligned (L1 index: 0); further corruption events will be suppressed
i'm use debian jessie with hand builded qemu 2.9.0, i'm try to
qemu-img check but it not helps. How can i recover data inside qcow2
file? (i'm not use compression or encryption inside it).
--
Vasiliy Tolstov,
e-mail: v.tolstov@selfip.ru
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] qemu 2.9.0 qcow2 file failed to open after hard server reset
2017-12-21 22:13 [Qemu-devel] qemu 2.9.0 qcow2 file failed to open after hard server reset Vasiliy Tolstov
@ 2017-12-21 22:58 ` John Snow
2017-12-22 9:23 ` Daniel P. Berrange
2017-12-27 21:47 ` Vasiliy Tolstov
0 siblings, 2 replies; 6+ messages in thread
From: John Snow @ 2017-12-21 22:58 UTC (permalink / raw)
To: Vasiliy Tolstov, qemu-devel; +Cc: Qemu-block
On 12/21/2017 05:13 PM, Vasiliy Tolstov wrote:
> Hi! Today my server have forced reboot and one of my vm can't start
> with message:
> qcow2: Marking image as corrupt: L2 table offset 0x3f786d6c207600
> unaligned (L1 index: 0); further corruption events will be suppressed
>
> i'm use debian jessie with hand builded qemu 2.9.0, i'm try to
> qemu-img check but it not helps. How can i recover data inside qcow2
> file? (i'm not use compression or encryption inside it).
>
Not looking good if you're missing the very first L2 table in its entirety.
You might be able to go through this thing by hand and learn for
yourself where the L2 table is (it will be a 64KiB region, aligned to a
64KiB boundary, that all contain 64bit, 64KiB aligned pointers that will
be less than the size of the file. the offset of this missing region is
not likely to be referenced elsewhere in your file.)
and then, once you've found it, you can update the pointer that's wrong.
However, where there's smoke there's often fire, so...
best of luck.
--js
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] qemu 2.9.0 qcow2 file failed to open after hard server reset
2017-12-21 22:58 ` John Snow
@ 2017-12-22 9:23 ` Daniel P. Berrange
2017-12-27 21:46 ` Vasiliy Tolstov
2017-12-27 21:47 ` Vasiliy Tolstov
1 sibling, 1 reply; 6+ messages in thread
From: Daniel P. Berrange @ 2017-12-22 9:23 UTC (permalink / raw)
To: John Snow; +Cc: Vasiliy Tolstov, qemu-devel, Qemu-block
On Thu, Dec 21, 2017 at 05:58:47PM -0500, John Snow wrote:
>
>
> On 12/21/2017 05:13 PM, Vasiliy Tolstov wrote:
> > Hi! Today my server have forced reboot and one of my vm can't start
> > with message:
> > qcow2: Marking image as corrupt: L2 table offset 0x3f786d6c207600
> > unaligned (L1 index: 0); further corruption events will be suppressed
> >
> > i'm use debian jessie with hand builded qemu 2.9.0, i'm try to
> > qemu-img check but it not helps. How can i recover data inside qcow2
> > file? (i'm not use compression or encryption inside it).
> >
>
> Not looking good if you're missing the very first L2 table in its entirety.
>
> You might be able to go through this thing by hand and learn for
> yourself where the L2 table is (it will be a 64KiB region, aligned to a
> 64KiB boundary, that all contain 64bit, 64KiB aligned pointers that will
> be less than the size of the file. the offset of this missing region is
> not likely to be referenced elsewhere in your file.)
Fun. That rather makes you wish that every single distinct type of table
in QCow2 files had a unique UUID value stored in it, to make forensics
like this easier :-)
Regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] qemu 2.9.0 qcow2 file failed to open after hard server reset
2017-12-22 9:23 ` Daniel P. Berrange
@ 2017-12-27 21:46 ` Vasiliy Tolstov
0 siblings, 0 replies; 6+ messages in thread
From: Vasiliy Tolstov @ 2017-12-27 21:46 UTC (permalink / raw)
To: Daniel P. Berrange; +Cc: John Snow, qemu-devel, Qemu-block
2017-12-22 12:23 GMT+03:00 Daniel P. Berrange <berrange@redhat.com>:
> On Thu, Dec 21, 2017 at 05:58:47PM -0500, John Snow wrote:
>>
>>
>> On 12/21/2017 05:13 PM, Vasiliy Tolstov wrote:
>> > Hi! Today my server have forced reboot and one of my vm can't start
>> > with message:
>> > qcow2: Marking image as corrupt: L2 table offset 0x3f786d6c207600
>> > unaligned (L1 index: 0); further corruption events will be suppressed
>> >
>> > i'm use debian jessie with hand builded qemu 2.9.0, i'm try to
>> > qemu-img check but it not helps. How can i recover data inside qcow2
>> > file? (i'm not use compression or encryption inside it).
>> >
>>
>> Not looking good if you're missing the very first L2 table in its entirety.
>>
>> You might be able to go through this thing by hand and learn for
>> yourself where the L2 table is (it will be a 64KiB region, aligned to a
>> 64KiB boundary, that all contain 64bit, 64KiB aligned pointers that will
>> be less than the size of the file. the offset of this missing region is
>> not likely to be referenced elsewhere in your file.)
Too hard, client restored backup because he don't want to wait for me =))
>
> Fun. That rather makes you wish that every single distinct type of table
> in QCow2 files had a unique UUID value stored in it, to make forensics
> like this easier :-)
>
=)
--
Vasiliy Tolstov,
e-mail: v.tolstov@selfip.ru
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] qemu 2.9.0 qcow2 file failed to open after hard server reset
2017-12-21 22:58 ` John Snow
2017-12-22 9:23 ` Daniel P. Berrange
@ 2017-12-27 21:47 ` Vasiliy Tolstov
2018-01-10 15:46 ` John Snow
1 sibling, 1 reply; 6+ messages in thread
From: Vasiliy Tolstov @ 2017-12-27 21:47 UTC (permalink / raw)
To: John Snow; +Cc: qemu-devel, Qemu-block
2017-12-22 1:58 GMT+03:00 John Snow <jsnow@redhat.com>:
>
>
> On 12/21/2017 05:13 PM, Vasiliy Tolstov wrote:
>> Hi! Today my server have forced reboot and one of my vm can't start
>> with message:
>> qcow2: Marking image as corrupt: L2 table offset 0x3f786d6c207600
>> unaligned (L1 index: 0); further corruption events will be suppressed
>>
>> i'm use debian jessie with hand builded qemu 2.9.0, i'm try to
>> qemu-img check but it not helps. How can i recover data inside qcow2
>> file? (i'm not use compression or encryption inside it).
>>
>
> Not looking good if you're missing the very first L2 table in its entirety.
>
> You might be able to go through this thing by hand and learn for
> yourself where the L2 table is (it will be a 64KiB region, aligned to a
> 64KiB boundary, that all contain 64bit, 64KiB aligned pointers that will
> be less than the size of the file. the offset of this missing region is
> not likely to be referenced elsewhere in your file.)
>
> and then, once you've found it, you can update the pointer that's wrong.
> However, where there's smoke there's often fire, so...
>
> best of luck.
>
> --js
If i use raw image as i understand this corruption can't happening in raw?
--
Vasiliy Tolstov,
e-mail: v.tolstov@selfip.ru
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Qemu-devel] qemu 2.9.0 qcow2 file failed to open after hard server reset
2017-12-27 21:47 ` Vasiliy Tolstov
@ 2018-01-10 15:46 ` John Snow
0 siblings, 0 replies; 6+ messages in thread
From: John Snow @ 2018-01-10 15:46 UTC (permalink / raw)
To: Vasiliy Tolstov; +Cc: qemu-devel, Qemu-block
On 12/27/2017 04:47 PM, Vasiliy Tolstov wrote:
> 2017-12-22 1:58 GMT+03:00 John Snow <jsnow@redhat.com>:
>>
>>
>> On 12/21/2017 05:13 PM, Vasiliy Tolstov wrote:
>>> Hi! Today my server have forced reboot and one of my vm can't start
>>> with message:
>>> qcow2: Marking image as corrupt: L2 table offset 0x3f786d6c207600
>>> unaligned (L1 index: 0); further corruption events will be suppressed
>>>
>>> i'm use debian jessie with hand builded qemu 2.9.0, i'm try to
>>> qemu-img check but it not helps. How can i recover data inside qcow2
>>> file? (i'm not use compression or encryption inside it).
>>>
>>
>> Not looking good if you're missing the very first L2 table in its entirety.
>>
>> You might be able to go through this thing by hand and learn for
>> yourself where the L2 table is (it will be a 64KiB region, aligned to a
>> 64KiB boundary, that all contain 64bit, 64KiB aligned pointers that will
>> be less than the size of the file. the offset of this missing region is
>> not likely to be referenced elsewhere in your file.)
>>
>> and then, once you've found it, you can update the pointer that's wrong.
>> However, where there's smoke there's often fire, so...
>>
>> best of luck.
>>
>> --js
>
> If i use raw image as i understand this corruption can't happening in raw?
>
Not this exact type of corruption, anyway. Backups are important for a
reason!
--js
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-01-10 15:46 UTC | newest]
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2017-12-21 22:13 [Qemu-devel] qemu 2.9.0 qcow2 file failed to open after hard server reset Vasiliy Tolstov
2017-12-21 22:58 ` John Snow
2017-12-22 9:23 ` Daniel P. Berrange
2017-12-27 21:46 ` Vasiliy Tolstov
2017-12-27 21:47 ` Vasiliy Tolstov
2018-01-10 15:46 ` John Snow
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