There is no single "optimum" chunk size per se. Larger chunk sizes
reduce the number of requests for larger files and sabotage performance
for smaller files. Obviously, if a file is smaller than
chunk_size*(no_of_disks-1) for RAID5 or chunk_size*no_of_disks for RAID0
then it cannot take advantage of the full speed of the array.
Similarly, if a file is smaller than chunk_size, performance will be no
better than on a single drive system or linear array. Someone correct
me if I'm wrong...
--
Jeremy Stanley Trend CMHS
Network Engineer http://www.trendcmhs.org
The opinions expressed herein do not necessarily
represent those of Trend CMHS or Trend Foundation.
"I program my homecomputer; beam myself into
the future." --Kraftwerk, 1981
> ----------
> From: Roeland M.J. Meyer[SMTP:[EMAIL PROTECTED]]
> Reply To: [EMAIL PROTECTED]
> Sent: Friday, July 30, 1999 10:17 AM
> To: Tom Livingston; Ingo Molnar
> Cc: [EMAIL PROTECTED]
> Subject: RE: raid0 vs. raid5 read performance
>
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED]]On Behalf Of Tom
> Livingston
> > Sent: Friday, July 30, 1999 1:02 AM
>
> > Others on this list seem to be confused as to how to
> > calculate an optimum
> > stripe size. Would this be a good thing to "get the word
> > out" on, or is there a more appropriate way to determine it?
>
> I have seen neither FAQ entry nor document nor email message giving
> any
> sort of heuristic to determine chunk size (even a note on what the
> unit
> of measurement is, would be nice). If someone could explain it to me,
> I
> would be happy to write it up.
>
