[rrd-users] Re: I know this is repetitive... but, is there a way to add a new DS to

[Hamish Marson]

Przemyslaw Karwasiecki wrote:

>On Tue, 2002-06-25 at 17:10, Hamish Marson wrote:
>(...snip...)
>  
>
>>Firstly, why do you assume that all data is cololected by SNMP? The bulk 
>>of mine is collected from a logfile (Postfix & amavisd logs)
>>
>>    
>>

[deleted]

>  
>
>>As it should be since it's the most ofthen used task. remember though 
>>with lots of files, just the open alone requires a linear search through 
>>the directory structure... That's a fair wack of IO just there...
>>
>>    
>>
>
>Two questions here: directory is a linear structure on disk -- true,
>but are you sure that once it is loaded (cached) to memory,
>(no more IO needed!), it is not hashed somehow to speed up lookups?
>
>  
>

If you have enough memory it will be cached. But my servers are always 
pretty busy. Especially the ones that I usually run rrd on. There's no 
hashing involved in the directory (Not unless you're using xfs from SGI 
I think).

>As far as my hardware -- it is pretty standard, P700 Linux 2.4 with 
>ext3fs on IDE drive.
>
>  
>

I run mine all on RS6000's AIX 4.3.3, and SSA-160 disk. Yes it's fast, 
but we tend to thrash the filesystems already. WHich means the memory is 
always wanted for something else. Usually ldap... Large directories... 
They thrash your memory (Unless you've got plenty). And updates will 
thrash it anyway.

Actually I did try a ramdisk with rrdtools as well last week. That was 
still quite slow. Especially on the first access. But then I also keep 
something like 40-80,000 rows of data...

-- 

I don't suffer from Insanity... 	| Linux User #16396
	I enjoy every minute of it...	|
					|
http://www.travellingkiwi.com/		|




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