Hi,

How-to-repeat :

I uploaded my table here :

ftp://support.mysql.com/pub/mysql/secret/parallelrecover.tar.gz

Then I'm experiencing random corruption using the -p switch :

myisamchk -p -o *.MYI <2:04:33 - recovering (with keycache) MyISAM-table 'searchmainhardwarefr0.MYI' Data records: 252447

myisamchk -a *.MYI <2:04:54 Checking MyISAM file: searchmainhardwarefr0.MYI Data records: 252447 Deleted blocks: 0 - check file-size - check key delete-chain - check record delete-chain - check index reference - check data record references index: 1 - check data record references index: 2

myisamchk -p -o *.MYI <2:05:02 - recovering (with keycache) MyISAM-table 'searchmainhardwarefr0.MYI' Data records: 252447

myisamchk -a *.MYI <2:05:11 Checking MyISAM file: searchmainhardwarefr0.MYI Data records: 252447 Deleted blocks: 0 - check file-size - check key delete-chain - check record delete-chain - check index reference - check data record references index: 1 - check data record references index: 2

l <2:05:14 total 13839 drwxr-sr-x 3 root mysql 216 Jan 14 02:05 . drwxr-sr-x 4 mysql mysql 14144 Jan 14 02:03 .. -rw-r----- 1 root mysql 7573410 Jan 14 02:05 searchmainhardwarefr0.MYD -rw-r----- 1 root mysql 6567936 Jan 14 02:05 searchmainhardwarefr0.MYI -rw-r----- 1 root mysql 8588 Jan 14 02:04 searchmainhardwarefr0.frm

myisamchk -p *.MYI <2:05:18 - parallel recovering (with sort) MyISAM-table 'searchmainhardwarefr0.MYI' Data records: 252447 - Fixing index 1 - Fixing index 2 myisamchk: warning: Duplicate key for record at 4602960 against record at 4602570 myisamchk: warning: Duplicate key for record at 4528290 against record at 4528020 myisamchk: warning: Duplicate key for record at 4536000 against record at 4535820 myisamchk: warning: Duplicate key for record at 4669680 against record at 4669560 myisamchk: warning: Duplicate key for record at 4460460 against record at 4459950 myisamchk: warning: Duplicate key for record at 4558080 against record at 4553880 myisamchk: warning: Duplicate key for record at 4558410 against record at 4558140 myisamchk: warning: Duplicate key for record at 4558320 against record at 4553640 myisamchk: warning: Duplicate key for record at 4572600 against record at 4555890 <cut>

One other try with a fresh copy :

myisamchk -p -o *.MYI <2:08:07 - recovering (with keycache) MyISAM-table 'searchmainhardwarefr0.MYI' Data records: 252447

myisamchk -a *.MYI <2:09:33 Checking MyISAM file: searchmainhardwarefr0.MYI Data records: 252447 Deleted blocks: 0 - check file-size - check key delete-chain - check record delete-chain - check index reference - check data record references index: 1 - check data record references index: 2

myisamchk -p -o *.MYI <2:09:39 - recovering (with keycache) MyISAM-table 'searchmainhardwarefr0.MYI' Data records: 252447

myisamchk -a *.MYI <2:09:48 Checking MyISAM file: searchmainhardwarefr0.MYI Data records: 252447 Deleted blocks: 0 - check file-size - check key delete-chain - check record delete-chain - check index reference - check data record references index: 1 - check data record references index: 2

l <2:09:55 total 13839 drwxr-sr-x 3 root mysql 216 Jan 14 02:09 . drwxr-sr-x 4 mysql mysql 14144 Jan 14 02:03 .. -rw-r----- 1 root mysql 7573410 Jan 14 02:09 searchmainhardwarefr0.MYD -rw-r----- 1 root mysql 6567936 Jan 14 02:09 searchmainhardwarefr0.MYI -rw-r----- 1 root mysql 8588 Jan 14 02:08 searchmainhardwarefr0.frm

myisamchk -p *.MYI <2:09:58 - parallel recovering (with sort) MyISAM-table 'searchmainhardwarefr0.MYI' Data records: 252447 - Fixing index 1 - Fixing index 2 Data records: 69905

l <2:10:07 total 4771 drwxr-sr-x 3 root mysql 216 Jan 14 02:10 . drwxr-sr-x 4 mysql mysql 14144 Jan 14 02:03 .. drwxr-sr-x 2 root mysql 192 Jan 14 02:04 backup -rw-r----- 1 root mysql 2097150 Jan 14 02:10 searchmainhardwarefr0.MYD -rw-r----- 1 root mysql 2757632 Jan 14 02:10 searchmainhardwarefr0.MYI -rw-r----- 1 root mysql 8588 Jan 14 02:08 searchmainhardwarefr0.frm

wow some datas are missing ;)

Sometimes I also got different MYI file size :

myisamchk -p -o *.MYI <2:12:09 - recovering (with keycache) MyISAM-table 'searchmainhardwarefr0.MYI' Data records: 252447 l <2:12:18 total 13831 drwxr-sr-x 3 root mysql 216 Jan 14 02:12 . drwxr-sr-x 4 mysql mysql 14144 Jan 14 02:03 .. -rw-r----- 1 root mysql 7573410 Jan 14 02:12 searchmainhardwarefr0.MYD -rw-r----- 1 root mysql 6561792 Jan 14 02:12 searchmainhardwarefr0.MYI -rw-r----- 1 root mysql 8588 Jan 14 02:12 searchmainhardwarefr0.frm

I hope you'll be able to reproduce the bug too, otherwise I'll try to reproduce it on my side in debug mode.

Regards, Jocelyn