[Dovecot] Dovecot very slow on a mailbox with > 700 IMAP Folders

[Becker, Ronny]

Am 05.05.2011 10:44, schrieb Timo Sirainen:
> On 5.5.2011, at 10.19, Timo Sirainen wrote:
>
>>> I did some debugging with strace, too. It's about 22MB only for running the lsub command !?
>> Run it with strace -tt and send me the output compressed?
> Ah, you have ACLs enabled. With ACLs it's looking up dovecot-acl file from each folder before returning it. This shouldn't be necessary with LSUB I think. I suppose some kind of an ACL cache could be a good idea some day too. And maybe a setting not to bother looking up ACLs for mailboxes in private namespaces.
>
> I'll try to do something about those within a few days..
>
Someone told me, that this problem should not happen when 
acl_shared_dict is used. But this was enabled in our setup. Is there any 
other workaround to use ACLs with such a large number of folders?!