Ramdrive

[Antony Stone]

On Thursday 25 September 2003 8:18 pm, Ugo Bellavance wrote:

>  Ram drive
>
>  Hi, how big should be a ramdrive to use it for MS's working directory?
>
>  I scan about 200 messages/day, my max inbound limit is 10 MB.  My average
> size is around 30KB

Two important items missing from the above numbers are how many emaisl you
prcoess at peak times (rather than the total number in 24 hours), and how
long the average email takes to scan.

Assume the latter is T seconds.

Then for the average load (not peak):

60 x 60 x 24 = 86400 seconds per day

86400 / 200 = 432 seconds available per email

If T is less than 432 (and it's likely to be more like 4.32!) then you will
rarely have more than one email in the queue, so you only need space for one
30kB message.

Let's assume someone sends the biggest email they can through your system
(10MB).   That means you need a 10MB working space.

Let's assume that at peak times, you're processing more than one email every
432 seconds (maybe as much as ten emails simultaneously!?).   That means you
need 10 x 10MB = 100MB working space.

As Raymond said, the standard usage for the ramfs is 50% of your physical
memory (but it will resize according to need), therefore unless you have less
than 256MBytes in your machine, I think you do not need to worry about such a
lightly-loaded system.

Antony.

--

Anything that improbable is effectively impossible.

 - Murray Gell-Mann, Nobel Prizewinner in Physics