Re: [GENERAL] Data corruption zero a file - help!!

[Noel Faux]

Thanks for all your help Michael, we wish to do a vacuum and dump before the upgrade to 8.02.  Do you believe this data corruption is a postgres issue of an OS / hardware issue? Cheers Noel Michael Fuhr wrote: On Thu, Mar 09, 2006 at 11:13:40AM +1100, Noel Faux wrote: Ok it worked but we ran into another bad block :( /vacuumdb: vacuuming of database "monashprotein" failed: ERROR: invalid page header in block 9022937 of relation "gap" / So the command we used was: dd bs=8k seek=110025 conv=notrunc count=1 if=/dev/zero of=/usr/local/postgresql/postgresql-7.4.8/data/base/37958/111685332.68 I'm tried to work out the formula for finding the file (i.e. the 111685332.*) to fix and the value to seek to, but as a complete novice I'm lost, any pointers would be a great help. We checked the block size and it's 8192. The database files are 1G, or 131072 8k blocks. The bad block you zeroed was 9022921; here's how you could have determined the file and block number within that file: test=> SELECT 9022921 / 131072 AS filenum, 9022921 % 131072 AS blocknum; filenum | blocknum ---------+---------- 68 | 110025 (1 row) The new bad block is 9022937 so the query would be: test=> SELECT 9022937 / 131072 AS filenum, 9022937 % 131072 AS blocknum; filenum | blocknum ---------+---------- 68 | 110041 (1 row) If you're running 7.4.8 then consider upgrading to 7.4.12. Offhand I don't know if any bugs have been fixed that might cause the problem you're seeing, but there have been other bug fixes.

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