Re: cache sizes & needed ram.

From: Dave Zarzycki <zarzycki@dont-contact.us>
Date: Wed, 16 Jul 97 21:36:44 -0700

> is there any refrence to which i can work out how much memory i
>would need to run squid(physical & swap) depending on the size of the
>cache?
>
> i'm running a 12gb cache on a 64mb machine, and untill recently
<snip...>

If I remember correctly a good rule of thumb is this:
(Somebody please correct me if I'm wrong.)

Take the amount of disk space and divide by your average object size. In
this case, I'll pick 20KB as an average object size.

12GB / 20KB = 630000 objects (small rounding to make life easy)

If my memory serves me correctly every object occupies about 100 bytes in
RAM to keep track of it.

630000 * 100B = 60MB of RAM just to keep track of objects!

This could easily increase if your average file is less:

12GB / 17KB avg. = 740000 objects
740000 * 100B = 70.5MB

Keep in mind that you still need RAM to cache objects and for objects in
transit! It would be wise to allocate an equal amount or more just to
cache files. Now add on the RAM necessary to keep your OS happy...

Have fun!

davez

----------------------------------------------------------------------
Dave Zarzycki Student
Workgroup Server QA Tester San Jose State University
Apple Computer, Inc. zarzycki@ricochet.net
zarzycki@apple.com dave@zarzycki.ml.org
----------------------------------------------------------------------

PGP Fingerprints:
DSS/Diffie-Hellman: CB9E 2621 B4BA 3F96 3516 B312 15B4 D842 3809 EF99
RSA: 8AF2 1040 8A9C D025 47BE 70DD A51C C887

Contact pgpkeys.mit.edu for my public keys.
Received on Wed Jul 16 1997 - 21:38:30 MDT

This archive was generated by hypermail pre-2.1.9 : Tue Dec 09 2003 - 16:35:47 MST