Thread: AW: WAL does not recover gracefully from out-of-disk-sp ace
> Regardless of whether this particular behavior is fixable, this brings > up something that I think we *must* do before 7.1 release: create a > utility that blows away a corrupted logfile to allow the system to > restart with whatever is in the datafiles. Otherwise, there is no > recovery technique for WAL restart failures, short of initdb and > restore from last backup. I'd rather be able to get at data of > questionable up-to-dateness than not have any chance of recovery > at all. It would imho be great if this utility would also have a means to extend a logfile, that was not extended to the full 16Mb, and revert the change that writes the whole file in the init phase. Imho this write at logfile init time adds a substantial amount of IO, that would better be avoided. If we really need this, it would imho be better to preallocate N logfiles and reuse them after checkpoint. Andreas
Zeugswetter Andreas SB <ZeugswetterA@wien.spardat.at> writes: > Imho this write at logfile init time adds a substantial amount of IO, > that would better be avoided. If we really need this, it would imho > be better to preallocate N logfiles and reuse them after checkpoint. Already done. See the WAL_FILES parameter. regards, tom lane
[ Charset ISO-8859-1 unsupported, converting... ] > > > Regardless of whether this particular behavior is fixable, this brings > > up something that I think we *must* do before 7.1 release: create a > > utility that blows away a corrupted logfile to allow the system to > > restart with whatever is in the datafiles. Otherwise, there is no > > recovery technique for WAL restart failures, short of initdb and > > restore from last backup. I'd rather be able to get at data of > > questionable up-to-dateness than not have any chance of recovery > > at all. > Update OPEN ITEMS list: Source Code Changes ------------------- Allow recovery from corrupted WAL file Finalize commit_delay value -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026