[aclug-L] Re: MTAs & maildir vs mbox (was Re: Virtual POP3 and IMAP server)

["Dale W Hodge" <dwh@xxxxxxxxxxxxxxxx>]

> -----Original Message-----
> From: discussion-bounce@xxxxxxxxx [mailto:discussion-bounce@xxxxxxxxx]On
> Behalf Of Jonathan Hall
> Sent: Friday, October 19, 2001 1:29 PM
> To: discussion@xxxxxxxxx
> Subject: [aclug-L] Re: MTAs & maildir vs mbox (was Re: Virtual POP3 and
> IMAP server)
>
>
>
> I know sometimes what seems like common sense doesn't necissarily pan out in
> the real world...
>
> But isn't it faster to read (and then delete) a single large file rather
> than reading then deleting a number of small files?
>
> I put together a quick 'n dirty bash script to test this theory... altho I
> realize this isn't the same as a real-world MTA/POP3 style test...  here are
> my results:
>
> (Test platform, if it matters to anyone, is Debian/Linux on a P133 w/ 64mb
> RAM and 6gb IDE HD)
>                                       Real    User    Sys
> Creating 1000 10kb files (with dd):   14.725  7.330   7.200
> Deleting 1000 10kb files:             10.733  5.230   5.410
> Creating 1 10,000kb file (with dd):   0.893   0.080   0.740
> Deleting 1 10,000kb file:             0.102   0.050   0.050
> Creating 10,000kb file, 10kb at a time:       12.567  6.600   5.830
> Deleting 10,000kb file, 10kb at a time:       After 14m51s I aborted this test
>
> The last test (deleting a partial file) is obviously where mbox suffers the
> greatest performance hit.

Actually, I don't think the mbox truely does an partial delete. I think it
merely copies the messages to a new file, skipping those parts marked for
deletion and then deletes the old file.  I can regularly purge a couple hundred
messages out of 1000 in less than 10 seconds.


--dwh

---
Dale W Hodge - dwh@xxxxxxxxxxxxxxxx
Secretary & Website Maintainer - info@xxxxxxxxx
Air Capital Linux User's Group  (ACLUG)
---


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