Srodne teme
06.07.2001. .qmail
24.01.2002. qmail how-to
15.06.2002. Flash knjiga na prodaju
17.10.2001. Delphi 4 knjiga
28.08.2002. qmail
13.12.2002. cron i MTA
02.11.2002. qmail i pine
13.12.2002. qmail+courier-imapd+squrrelmail
13.08.2003. Qmail i BIND
23.11.2003. Export mailova
Navigacija
Lista poslednjih: 16, 32, 64, 128 poruka.

mbox vs Maildir

[es] :: Linux/UNIX serveri i servisi :: mbox vs Maildir

[ Pregleda: 3187 | Odgovora: 0 ] > FB > Twit

Postavi temu Odgovori

Autor

Pretraga teme: Traži
Markiranje Štampanje RSS

stinger
Luka Gerzic
DELTA M, IT Department
DELTA M HQ

Član broj: 126
Poruke: 1099
*.drenik.net

ICQ: 57419599
Sajt: www.gerzic.net


Profil

icon mbox vs Maildir08.11.2002. u 12:20 - pre 260 meseci
Dosta cesto me pitaju zasto koristim qmail i zasto je Maildir bolji od mbox-a, e sad da ja to ne bih objasnjavao svakom ponaosob, i da ne bih iznova pricao zasto koristim qmail evo link-a i dela texta koji su odradili profesionalci (znaci zakljucna rec je ispod, ostatak texta sa testovima pogledajte na linku ispod)

Pozdrav... :)


--- snip ---
Final Analysis
These results easily reject an absolute claim that maildirs always fail to scale to large mail folders. These benchmarks show that a big factor is the underlying hardware and the operating system. The ext2 filesystem, as implemented by the Linux kernel, is known for its speed and good performance.[4]

Maildirs will not scale very well on servers that use old, slow, hardware. Maildirs will also do poorly with an inefficient filesystem that stores very large folders which are frequently searched for specific content. However maildirs' performance should be adequate even on slow machines with very large folders, as long as the mail activity is just occasional read/write access, and browsing. Even with large folders, containing unread messages, maildirs will require less system load than mboxes. On fast hardware, these benchmarks indicate that maildirs scale better in more often than not. Maildirs scale much better with mail folders that contain large messages. Even with folders that have a large number of smaller messages, maildirs did better than mboxes on many benchmarks.

It should be noted that some of these numbers reflect the overall system performance that may differ from the apparent performance seen by a mail client. When running the benchmark, the UW-IMAP server did not actually take much longer to open a 2,000 message folder than Courier-IMAP -- it postponed the mbox file rewrite until the folder was closed. However, this benchmark takes both measurements into account. From the user's standpoint, some of the delay in opening a large folder is postponed until the folder is closed. This results in a slightly faster response when opening a folder, but from the system's viewpoint the load's the same. This is why both measurements are important. Whether you take the load up front, or spread it around, the grand total is still the same. The decision to postpone rewriting the mbox file can result in some savings in time (mostly by consolidating multiple rewrites into one). However, there's also a down side to this approach. An IMAP server can always be killed by an abnormal system event, for example. When that happens to the UW-IMAP server, any unsaved changes to the folder will be lost.

Mail clients that do not cache IMAP metadata may also result in degraded maildir performance. The Pine mail client doesn't do any caching; it pretty much reads the message index every time it opens the folder, which is usually an expensive operation for maildirs. Most Windows mail clients cache IMAP metadata extensively. IMAP mail clients that support offline use MUST cache IMAP metadata. Both Netscape Mail, Outlook, and Outlook Express, usually cache everything they receive from the IMAP server. They will not ask for the entire message index, again, and therefore avoid most of maildir's message index penalty. If they open a folder and see no changes since the last IMAP session, they will do absolutely nothing. Therefore, another factor to consider is the mail client software that will be used to access the mailbox.

The final conclusion is that -- except in some specific instances -- using maildirs will be just as fast -- and in sometimes much faster -- than mbox files, while placing less of a load on the rest of the mail system. The claims in the UW-IMAP server's documentation regarding maildir performance can be supported only in certain, specific, very narrowly-defined conditions. There is no simple answer on which mail storage format is better. A lot depends on many variables that vary widely in different situations. Besides the raw benchmarks shown above, other factors include the mail server software being used, what kind of storage is being used, and the available network bandwidth. The final answer depends on all of the above.

--- snap ---


Link je sledeci (ako vas interesuje kompletan text sa testovima)
http://www.courier-mta.org/mbox-vs-maildir/


 
Odgovor na temu

[es] :: Linux/UNIX serveri i servisi :: mbox vs Maildir

[ Pregleda: 3187 | Odgovora: 0 ] > FB > Twit

Postavi temu Odgovori

Srodne teme
06.07.2001. .qmail
24.01.2002. qmail how-to
15.06.2002. Flash knjiga na prodaju
17.10.2001. Delphi 4 knjiga
28.08.2002. qmail
13.12.2002. cron i MTA
02.11.2002. qmail i pine
13.12.2002. qmail+courier-imapd+squrrelmail
13.08.2003. Qmail i BIND
23.11.2003. Export mailova
Navigacija
Lista poslednjih: 16, 32, 64, 128 poruka.