Greg Stark <gsstark@mit.edu> writes:
> I've seen some pretty severe damage caused by calling sync(2) on a loaded
> system. The system in question was in the process of copying data to an NFS
> mounted archival site. When the sync hit basically everything stopped until
> the buffered network writes could be synced. The live database was basically
> frozen for a few seconds and the web site nearly crashed. The sysadmin had to
> send out a notice asking everybody to refrain from using sync until the
> archival process had completed.
This seems, um, hard to believe. Did he shut down the standard syncer
daemon? I have never seen a Unix system that would allow more than
thirty seconds' worth of unwritten buffers to accumulate, and would not
care to use one if it existed.
regards, tom lane