Re: [exim] How to force exim to load file with whitelist IPs…

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Auteur: Chris Knipe
Date:  
À: exim-users
Sujet: Re: [exim] How to force exim to load file with whitelist IPs into memory
Put the text file on a small md partition? :)


On Wed, Nov 2, 2011 at 2:14 PM, Jakob Hirsch <jh@???> wrote:
> Phil Pennock, 2011-10-31 08:41:
>
>> You've mounted the filesystem with "atime" support, which reports last
>> access time.  While useful, for busy file-systems this default support
>> in Unix has proven to be a historical mistake (in my opinion).
>>
>> The only reason the disk is being affected here is because the act of
>> reading the file is updating the inode with a new atime, and this needs
>> to be written back to the disk.  Otherwise, assuming local disk and not
>> NFS, the file would sit in buffer cache and all new reads would never go
>> to disk, because the cache would still be valid.
>
> I second your opinion. atime is kind of a broken concept. OTOH, atime
> updates are cached (AFAIK), so the impact should only be visible on very
> busy systems with little RAM.
>
>> Mount the filesystem noatime or move the file to a filesystem which is
>> mounted noatime and see how that affects performance.
>
> btw, Linux uses relatime by default since 2.6.30.
>
>> CDB is probably the way to go then.
>
> CDB (and DBM etc.) cannot be used with iplsearch. We would need a trie
> data structure for that. Don't know if there are widely used standard
> formats and tools for that...
>
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--

Regards,
Chris Knipe