[Dovecot] index IO patterns

[Cor Bosman]

Hi javier,

> 
> 
> Indexes are very random, mostly read, some writes if using
> dovecot-lda (ej: dbox). The average size is rather small, maybe 5 KB in
> our setup. Bandwith is rather low, 20-30 MB/sec 

Even without LDA/LMTP dovecot-imap needs to write right? It would 
need to update the index every time an imap connect happens and
new mails are found in the mail store.

Cor