pdflush on Linux
Posted on 2008-02-01
I'm running a server which continuously receives data over a network,
processes the data, and stores the processed data in a large
database. The database consists of multiple files which are very
large ( > 50GBs). The database has a lot of cache, to get around I/O
But what happens is that the system starts to slow down horribly
despite database cache, and the iostat monitoring tool along with atop
indicates constant disk activity. When I shut the server down, disk
activity continues for some time, even though the server is off.
I'm wondering if this is an issue with pdflush. There's no utility on
Linux to indicate which process is actually doing the disk I/O, but I
suspect pdflush is the cause of the performance bottleneck. My
1. Is pdflush a likely candidate for this problem?
2. If so, is there anything I can do about it, such as disable
pdflush, or modify how often it flushes pages to disk.