In message <[EMAIL PROTECTED]>, Eric Anderson writes: >If I write a 10GB file to disk (RAID array has 1GB cache, system has 1GB >memory), then I should definitely see better read performance reading >that same file back to /dev/null than writing it, right?
Nope, quite the contrary: you will get much better write performance because your write operation finishes the moment it has hit the cache, but your read request only comes fast if it happens to be in the cache. With a 1GB cache and a 10GB file, this clearly will not be the case unless some kind of very good read-ahead happens in the RAID5 unit. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "[EMAIL PROTECTED]"
