He1p Required - Please??? (fwd)

[UC Berkeley Usenet Administrator]

hi,

> Is this actually the wrong advice then?  Should I be using a smaller
> interleave for my CCD stripe? (I'm using the stripe for the history and
> overview databases)

you might want to look at http://www.lemis.com/vinum.html
(or for the less web-prone try vinum(4) and vinum(8)).

these are the docs for the vinum volume manager and in it greg lehey gives
a very good explanation of the issue of stripe size choice.  it's written
obviously with an eye towards that software, but the same principles
should apply for ccd or any other raid software.  i'm using 256k with ccd,
vinum, and SunODS 4.2 (on three different machines, obviously).  on a
FreeBSD-3.2-STABLE box i'm seeing ~20ms article write times (4-4GB UW
barracudas, tradspool, softupdates enabled, no binaries), which i believe
is pretty decent performance.  this is for the spool, and overview/history
has slightly different considerations.  i'd be inclined to go with
something between 256k and 2mb for those, but i don't have any evidence to
support that statement.

chris