On 2011-10-30 at 10:51 +0100, [email protected] wrote: > but when I check stat of file /etc/my_whitelist I get information that this > file was accessed when exim checked for data in this file.
You've mounted the filesystem with "atime" support, which reports last access time. While useful, for busy file-systems this default support in Unix has proven to be a historical mistake (in my opinion). The only reason the disk is being affected here is because the act of reading the file is updating the inode with a new atime, and this needs to be written back to the disk. Otherwise, assuming local disk and not NFS, the file would sit in buffer cache and all new reads would never go to disk, because the cache would still be valid. Unless your system has so little RAM and the file is accessed so infrequently that it doesn't remain in cache. But in that case the extra delay loading the file in should be insignificant in the scheme of things. Mount the filesystem noatime or move the file to a filesystem which is mounted noatime and see how that affects performance. If a linear scan of a small (<200kB) file which is rarely modified and so sits permanently is cache is too slow, there are file-formats for rarely-modified data which reduce the amount of the "disk" file to be read (so reduce the amount of RAM scanned through when using the cache). CDB is probably the way to go then. -Phil -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
