Greg Louis <glouis@dynamicro.on.ca> wrote: > > Here's the ext3 part. On another machine I got the following times to > build that list of 530,000 tokens, starting by creating empty db files > on a partition mounted as: How large are the generated output files? > ... > Some further findings: > > o It doesn't matter if the source (mbox) file is on ext3/ordered or > ext2; the difference in time is insignificant. > > o Just processing a message to classify it takes about four times as > long if the .db files are on ext3/ordered as it does if the .db > files are on ext2. I would be suspecting that the database is opening the files with O_SYNC or is running fsync or such. Maybe. > o Dumping the tokens and counts from the database in text form and > reloading them into a new database file is not subject to serious > performance problems; on the machine that needs 24 minutes to > build from a 200-Mb mbox, rebuilding the database from a list of > tokens took eight seconds -- this was on ext3 in ordered mode. How does this operation differ from the operation which is "slow"? > These data were obtained on machines running linux kernels > 2.4.21-pre3-ac4 and -ac5 and 2.4.21-pre4-ac1; kernel 2.4.20-ac2 appears > to give similar results though this has not been thorougly tested. > Results like those reported were initially obtained with db-3.1.17; the > tests shown here used db-4.1.25. > > More info available on request; tuning hints most gratefully received > and tested. If you can suggest an easy way in which I can reproduce this, that would be efficient. _______________________________________________ Ext3-users@redhat.com https://listman.redhat.com/mailman/listinfo/ext3-users
