Обсуждение: [GENERAL] Recovery damaged dump file

On Thu, Mar 9, 2017 at 8:55 PM, mac pack <mac.apxz@gmail.com> wrote:
> pg_restore  db.backup > out.sql
>
> pg_restore: [custom archiver] unrecognized data block type (0) while
> searching archive
>
> The follow commands works fine:
> pg_restore  -s db.backup > out.sql
> pg_restore -l db.backup

If you are lucky and as -l is able to print out the complete list of
objects and is able to dump all the schema, perhaps not everything is
lost. You may want to restore a limited set of objects by using
--use-list first, and see what can be saved.

> Do you think it's possible to recover the dump file, is there any method or
> tool to recover dump files?

Lost data would be lost. Likely you can still recover portions of it,
perhaps most of it.
--
Michael

On 03/09/2017 03:55 AM, mac pack wrote:
> Hi.
>
> My PostgreSQL server was affect by a Ransomware virus. I'm trying to
> restore the database from a dump file made by pg_dump in custom format
> (-F c option), but the dump file seems to be damaged in the first's 1000
> lines.
>
> Opening the file with vi shows ^@^@^@^@^@^@^@^@^@^@^ followed by part of
> the databse schema and the a lote of lines with binary characters that i
> think is the table's data.

The custom format is a binary format so non text characters would be
expected.

Did you try to restore using the file, before doing the below?

If there was an error when you did that and if so what was it?

>
> I tried to replace those first lines with lines from other dev database
> and i can run pg_restore but at some point throws error.
>
> pg_restore  db.backup > out.sql
>
> pg_restore: [custom archiver] unrecognized data block type (0) while
> searching archive
>
> The follow commands works fine:
> pg_restore  -s db.backup > out.sql
> pg_restore -l db.backup
>
> Do you think it's possible to recover the dump file, is there any method
> or tool to recover dump files?
>
>
> Thanks.
> Mário


--
Adrian Klaver
adrian.klaver@aklaver.com

On 03/09/2017 09:09 PM, Adrian Klaver wrote:
> On 03/09/2017 03:55 AM, mac pack wrote:
>> Hi.
>>
>> My PostgreSQL server was affect by a Ransomware virus. I'm trying to
>> restore the database from a dump file made by pg_dump in custom format
>> (-F c option), but the dump file seems to be damaged in the first's 1000
>> lines.
>>
>> Opening the file with vi shows ^@^@^@^@^@^@^@^@^@^@^ followed by part of
>> the databse schema and the a lote of lines with binary characters that i
>> think is the table's data.
>
> The custom format is a binary format so non text characters would be
> expected.
>
> Did you try to restore using the file, before doing the below?
>
> If there was an error when you did that and if so what was it?

Should be:

Was there an error when you did that and if so what was it?

>
>>
>> I tried to replace those first lines with lines from other dev database
>> and i can run pg_restore but at some point throws error.
>>
>> pg_restore  db.backup > out.sql
>>
>> pg_restore: [custom archiver] unrecognized data block type (0) while
>> searching archive
>>
>> The follow commands works fine:
>> pg_restore  -s db.backup > out.sql
>> pg_restore -l db.backup
>>
>> Do you think it's possible to recover the dump file, is there any method
>> or tool to recover dump files?
>>
>>
>> Thanks.
>> Mário
>
>


--
Adrian Klaver
adrian.klaver@aklaver.com

On 03/10/2017 01:25 AM, mac pack wrote:
>
> 2017-03-10 5:11 GMT+00:00 Adrian Klaver <adrian.klaver@aklaver.com
> <mailto:adrian.klaver@aklaver.com>>:
>
>     On 03/09/2017 09:09 PM, Adrian Klaver wrote:
>
>         On 03/09/2017 03:55 AM, mac pack wrote:
>
>             Hi.
>
>             My PostgreSQL server was affect by a Ransomware virus. I'm
>             trying to
>             restore the database from a dump file made by pg_dump in
>             custom format
>             (-F c option), but the dump file seems to be damaged in the
>             first's 1000
>             lines.
>
>             Opening the file with vi shows ^@^@^@^@^@^@^@^@^@^@^
>             followed by part of
>             the databse schema and the a lote of lines with binary
>             characters that i
>             think is the table's data.
>
>
>         The custom format is a binary format so non text characters would be
>         expected.
>
>         Did you try to restore using the file, before doing the below?
>
>
> yes
>
>
>         If there was an error when you did that and if so what was it?
>
>
>     Should be:
>
>     Was there an error when you did that and if so what was it?
>
>
> pg_restore db.bckup > out.sql
> pg_restore: [archiver] input file does not appear to be a valid archive
>
> Opening the original damaged file in vi with :%!xxd it show's:

So something zeroed out the beginning of the file.

I know you said:

pg_restore  -s db.backup > out.sql

works. Does the opposite work also?:

pg_restore  -a db.backup > out.sql

I would say start with Michael's suggestion of working through object by
object.

You mentioned another dev database, how close is that to the content of
the damaged database?


>
> 0003ff80: 0000 0000 0000 0000 0000 0000 0000 0000  ................
> 0003ff90: 0000 0000 0000 0000 0000 0000 0000 0000  ................
> 0003ffa0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
> 0003ffb0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
> 0003ffc0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
> 0003ffd0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
> 0003ffe0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
> 0003fff0: 0000 0000 0000 0000 0000 0000 0000 0000  ................
> 00040000: 3331 3820 2020 2020 2020 2020 2020 202d  318            -
> 00040010: 272c 206e 756c 6c29 3b0d 0a69 6e73 6572  ', null);..inser
> 00040020: 7420 696e 746f 206d 6f72 6164 6173 6374  t into moradasct
> 00040030: 7428 6964 5f64 6973 7463 6f6e 632c 206c  t(id_distconc, l
> 00040040: 6f63 616c 6964 6164 652c 2061 7272 7561  ocalidade, arrua
> 00040050: 6d65 6e74 6f2c 2074 726f 636f 2c20 6c69  mento, troco, li
> 00040060: 6d5f 696e 6665 7269 6f72 5f70 6f72 7461  m_inferior_porta
> 00040070: 2c20 636c 6965 6e74 652c 2063 6f64 6967  , cliente, codig
> 00040080: 6f5f 706f 7374 616c 2c20 6c69 6d5f 7375  o_postal, lim_su
> 00040090: 7065 7269 6f72 2920 7661 6c75 6573 2028  perior) values (
>
>
>
>
>
>
>             I tried to replace those first lines with lines from other
>             dev database
>             and i can run pg_restore but at some point throws error.
>
>             pg_restore  db.backup > out.sql
>
>             pg_restore: [custom archiver] unrecognized data block type
>             (0) while
>             searching archive
>
>             The follow commands works fine:
>             pg_restore  -s db.backup > out.sql
>             pg_restore -l db.backup
>
>             Do you think it's possible to recover the dump file, is
>             there any method
>             or tool to recover dump files?
>
>
>             Thanks.
>             Mário
>
>
>
>
>
>     --
>     Adrian Klaver
>     adrian.klaver@aklaver.com <mailto:adrian.klaver@aklaver.com>
>
>


--
Adrian Klaver
adrian.klaver@aklaver.com

On Mon, Mar 13, 2017 at 7:40 PM, mac pack <mac.apxz@gmail.com> wrote:
> Any one knows how pg_dump saves the dump in custom format. What is the
> structure of the format, there is any doc about that?

There are no docs, but the code in src/bin/pg_dump/pg_backup_custom.c
can speak by itself if you are willing to know what each byte is
allocated for.
--
Michael