innodb_fast_checksum caveat

I posted a forum issue about a page fault I had will restoring a backup made on a Ubuntu 10.04 server to a Ubuntu 9.10 server and first assumed there was some issue with the version of the OS. I had this same problem with a backup made on a Debian Lenny server and restoring on an Ubuntu 10.04 server.

It turns out that the issue is that if the backup is made on a server with “innodb_fast_checksum=1” turned on, you will get this error if you try to use a restored (prepared) backup on a box NOT using innodb_fast_checksum. This also includes using the generated backup file “backup-my.cnf”, which even if you make a backup on a server using fast checksum, this file will NOT have innodb_fast_checksum specified and starting MySQL with this file will result in the failure I had listed in my previous forum post:

10301 1:18:35 InnoDB: Page dump in ascii and hex (16384 bytes):
len 16384; hex 6c641a4e00000005000000000000000000000016946dfe1600

huge dump of 000s and fffs
InnoDB: End of page dump
110301 1:18:35 InnoDB: Page checksum 1300381512 (32bit_calc: 1818499662), prior-to-4.0.14-form checksum 1119544184
InnoDB: stored checksum 1818499662, prior-to-4.0.14-form stored checksum 1119544184

I don’t know if this is documented, but if it isn’t, I’d be glad to get it documented for you if you give me the details of submitting such a contribution.

I will draw Fred’s attention to this. I also filed a bug against xtrabackup.

Hey there,

Is there a bug for this logged? It bit me again this morning, but for some reason the only way I could get around it this time was to supply “–innodb-fast-checksum” on the command line during a prepare. Maybe I’ll chat with Stew :slight_smile: