Re: Suitable system

Dear all,

> You need more memory if supporting that much cache..
>
> 4 * 6.2GB = 24.8GB
> 20KB on average / object -> 24.8GB/20KB = 1.3M objects
> 100 bytes metadata (always in memory) / object -> 124MB metadata (this
> is regardless you are using NOVM or not).
>
> So I'd say at least 256MB. The OS needs a few MB, and it is good to have
> some memory for filesystem cache....
>
True... You needs lots of memory.. Even with the NOVM squid...
Every object takes about 64-Byte in core memory.. The main objective is to
have no paging and/or swapping activity.. It's easy to calculate the needed
memory when you know the size of the disk..
If you have a cache disk of 16-GByte, and assuming the average object-size is
4-KByte, and the HOT-Cache is "0-bytes" (the NOVM uses no Hot-cache) and the
RAM usage of the AIX system is about 64-MByte, the total RAM needed in the
system is: 64M+ (16*1024 * 64/(1024*4)) = 320-MByte

I always use a simple formula to calculatie the average disk-size:
   DS = 60 * (M - H - S)
DS = Disk size in MByte
 M = RAM size in MByte
 H = Size in MByte of Hot-cache
 S = size of needed RAM by OS etc..

 DS = 60 * (320 - 0 -64) = 15360-MByte

Cheers, Henny

> ---
> Henrik Nordström
>
> Umar Goldeli wrote:
>
> > This cache will run on a P166/Linux and will have 128M RAM to start with
> ....
>
> > Filesystem blocksize will be 8k. And as stated before, there will be 4 *
> > 6.2gb cache_dirs.
>
>

-- 
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