On 2/7/18 13:34, Bossart, Nathan wrote: > Here is a patch to allow users to change the WAL segment size of a cluster > with > pg_resetwal. Like the '--wal-segize' option in initdb, the new '-s' option > accepts segment sizes in megabytes.
Or how about we call the new option, um, --wal-segsize? > The first is a division-by-zero error caused when the control data must be > guessed. If the control data is damaged, WalSegSz will not be set to the > guessed WAL segment size, resulting in an error during XLogFromFileName(). > The > attached patch resolves this issue by ensuring WalSegSz is set to a valid > value > after either reading or guessing the control values. I noticed this issue in pg_controldata too. Maybe that should be combined in a separate patch. > Note that some segment size changes will cause old WAL file names to be > reused. > The new documentation for '-s' contains a note warning of this side effect. I > considered a couple of strategies to prevent this, but I chose not to include > any in the patch based on previous correspondence in this thread. If file > name > overlap is an issue, users can already use the '-l' option to set a safe WAL > starting address. The patch "Configurable file mode mask" contains the beginning of a test suite for pg_resetwal. It would be great if we could get a test case for this new functionality implemented. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
