4 ms·
> double write buffers were disabled on a non-atomic FS Surely just sending SIGKILL will allow the writes already issued to complete, regardless of the FS type
by yuubi 12y ago
> double write buffers were disabled on a non-atomic FS
Surely just sending SIGKILL will allow the writes already issued to complete, regardless of the FS type/options? Nobody kicked the plug out of the wall.
- falcolas 12y agoDouble write buffers help to validate that the pages were written to disk correctly. Otherwise, there's no way to tell if a complete page was written, since writing 16k pages to disk is not an atomic operation. InnoDB writes to the doublewrite buffer (an internal tablespace on disk), then the record in place. If the two do not match on recovery, the record is considered not written, and rebuilt from the transaction log. If the doublewrite buffer is disabled, then InnoDB has no way of telling if the write to the page on disk was started, completed, or partially completed. This causes corruption.