Re: What's a Reasonable Inbox Size?

2020-05-09 Thread @lbutlr
On 08 May 2020, at 12:54, a...@globalchangemusic.org wrote:
>> It depends on what you consider reasonable.
>> 
>> The processing time of file operation that iterates through a mailbox
>> will generally go up proportinately with size.  If you do a text search
>> without some indexing system like Solr, it will take a very long time.
>> 
>> If the mailbox is just some archive that you pile up and forget about it
>> except for once in a blue moon retrieval, then it might be reasonable.
>> 
>> If it's an active mailbox, it will be a pain to navigate, in the same
>> way a single folder with 100K files or a file cabinet with huge stacks
>> of envelopes.
>> 
>> I would guess some partioning of the large mailboxes into smaller
>> mailboxes would help with active mailboxes.  Most people spend most of
>> their time on new/recent messages, so making time or size or subject
>> based volmes wouldn't be a bad idea.
>> 
>> If the bulk of the size are redundant copies of attachments, then Dovecot's
>> *dbox support de-duping which would aso help.
> 
> So, generally speaking, you don't want to have inboxes that just sync all day 
> long, due to massive amounts of small files in the inbox.  This may be OK in 
> the case of a rarely accessed archive folder, but not good for regularly 
> accessed inboxes, etc.?

Not really since most GUI clients keep all the folders synced, so moving files 
to different, smaller count mailboxes doesn’t reduce the number of files 
accessed.

The issue is if you have a folder with millions of files in it, most file 
systems don’t deal well with this.

But with mbox, each “folder” is a single file, and making a single multi-GB 
text file that has to be parsed is a definitely issue on any file system.


-- 
ALL WORK AND NO PLAY MAKES BART A DULL BOY ALL WORK AND NO PLAY MAKES
BART A DULL BOY ALL WORK AND NO PLAY MAKES BART A DULL BOY Bart
chalkboard Ep. 1F07




Re: What's a Reasonable Inbox Size?

2020-05-08 Thread Joseph Tam

On Fri, 8 May 2020, Joseph Tam wrote:


It depends on what you consider reasonable.


Whoops.  Editing error.  What I wanted to send.

On Fri, 8 May 2020, a...@globalchangemusic.org wrote:

So, generally speaking, you don't want to have inboxes that just sync all day 
long, due to massive amounts of small files in the inbox.


I don't know enough about what is involved when your client tries
to sync to comment on your particular situation.  If the exchange of
information involves only delta changes (e.g. list datum that have been
added/removed since the last sync), and if this information is readily
available in Dovecot's caches, then this operation might be optimized
to take minimal time.

If however, it involves exchanging entire lists of many messages IDs,
or worse, involves Dovecot accessing each message, it will result in
large amounts of time spent in I/O (network, disk or both).  With Maildir
(many small message in a folder), this causes seeking all over the disk.
Some filesystems (XFS?) may be better at this than others.

The description of your problem seems to suggest the latter, so breaking
up gigantic mailboxes into manageable volumes will help.

If you really want to see what's going on when a client syncs, you
can network trace, process trace, or use Dovecot's rawlog feature

https://wiki.dovecot.org/Debugging/Rawlog

to directly observe the iteraction between a server and client.


This may be OK in the case of a rarely accessed archive folder, but not
good for regularly accessed inboxes, etc.?


This is not really so much technical advice as a rule of thumb: there's
not a lot of payoff to optimizing rare operations.

Joseph Tam 


Re: What's a Reasonable Inbox Size?

2020-05-08 Thread Joseph Tam

On Fri, 8 May 2020, a...@globalchangemusic.org wrote:




It depends on what you consider reasonable.

The processing time of file operation that iterates through a mailbox
will generally go up proportinately with size.  If you do a text search
without some indexing system like Solr, it will take a very long time.

If the mailbox is just some archive that you pile up and forget about it
except for once in a blue moon retrieval, then it might be reasonable.

If it's an active mailbox, it will be a pain to navigate, in the same
way a single folder with 100K files or a file cabinet with huge stacks
of envelopes.

I would guess some partioning of the large mailboxes into smaller
mailboxes would help with active mailboxes.  Most people spend most of
their time on new/recent messages, so making time or size or subject
based volmes wouldn't be a bad idea.

If the bulk of the size are redundant copies of attachments, then Dovecot's
*dbox support de-duping which would aso help.



So, generally speaking, you don't want to have inboxes that just sync all day 
long, due to massive amounts of small files in the inbox.  This may be OK in 
the case of a rarely accessed archive folder, but not good for regularly 
accessed inboxes, etc.?







Joseph Tam 


Re: [External] What's a Reasonable Inbox Size?

2020-05-07 Thread @lbutlr
On 07 May 2020, at 10:40, Kevin A. McGrail  wrote:
> We find that large inboxes are bad for the server and bad for the client
> because the MUAs just don't handle it well either.  1 or 2GBs and you
> start to see issues.

Which is a good reason to move off mbox. There are several other much superior 
choices and as far as I know there is no reason to use mbox. 


-- 
Minds are like parachutes, they only work when they are open.




Re: What's a Reasonable Inbox Size?

2020-05-07 Thread Joseph Tam

On Thu, 7 May 2020, Asai wrote:


I have several users who have inboxes that are over 20 GB.

As email admins,  how do you handle inboxes that are so large? Do you use 
mailbox types that have better performance like dbox? We're using maildir.


What's a reasonable inbox size?  Is 20+ GB reasonable and nothing to worry 
about?


It depends on what you consider reasonable.

The processing time of file operation that iterates through a mailbox
will generally go up proportinately with size.  If you do a text search
without some indexing system like Solr, it will take a very long time.

If the mailbox is just some archive that you pile up and forget about it
except for once in a blue moon retrieval, then it might be reasonable.

If it's an active mailbox, it will be a pain to navigate, in the same
way a single folder with 100K files or a file cabinet with huge stacks
of envelopes.

I would guess some partioning of the large mailboxes into smaller
mailboxes would help with active mailboxes.  Most people spend most of
their time on new/recent messages, so making time or size or subject
based volmes wouldn't be a bad idea.

If the bulk of the size are redundant copies of attachments, then Dovecot's
*dbox support de-duping which would aso help.

Joseph Tam 


Re: [External] Re: What's a Reasonable Inbox Size?

2020-05-07 Thread Kevin A. McGrail
On 5/7/2020 12:56 PM, Asai wrote:
> That makes sense.  So you're saying that very large inboxes are
> generally bad for mobile devices?  How are they bad for the servers? 

I'm saying that large inboxes can be generally bad for MUAs including
mobile and desktop.  Their just downloading and constantly grinding
through data that isn't really being used.  Same thing for the server.

If you have an inbox with 10K emails, are you reading them all?  No, but
you are likely checking the inbox every 5 mins.

And if you have a 20GB INBOX and you download it on mobile, depending on
the MUA and settings, you might be just using a ton of cell data and
storage on your phone.

Dovecot, of course, has intelligent caching and that helps a ton but
overall it's an efficiency thing.  Though not that long ago, it was also
a way of keeping some MUAs like Outlook from crashing when the PST / OST
file got too large.

Regards,

KAM



Re: What's a Reasonable Inbox Size?

2020-05-07 Thread Benny Pedersen

On 2020-05-07 18:56, Asai wrote:


That makes sense.  So you're saying that very large inboxes are
generally bad for mobile devices?  How are they bad for the servers?


aquamail have local cache upto 1 last emails, and it does not fetch 
more then that, so basicly if all android users have all mail in inbox 
and useds aquamail it will work, i have over 30 emails around 7GB 
totaly, if all this was in inbox will bring down thunderbird, since it 
fetches all 30 email to offline stata as default, this also happens 
with outlook, sadly


in roundcube i make all mails into mountly folders with brings down 
amount of emails into lower subdirs on dovecot, with will then be speedy


it would be nice to know how to generic speed it up to google standards, 
virtual folder trick ?


Re: What's a Reasonable Inbox Size?

2020-05-07 Thread Sami Ketola



> On 7. May 2020, at 18.39, Asai  wrote:
> 
> Greetings,
> 
> I have several users who have inboxes that are over 20 GB.
> 
> Lately I have noticed Dovecot logs say it's taking over 30 seconds to sync 
> their mailboxes.
> 
> As email admins,  how do you handle inboxes that are so large? Do you use 
> mailbox types that have better performance like dbox? We're using maildir.
> 
> What's a reasonable inbox size?  Is 20+ GB reasonable and nothing to worry 
> about?
> 
> Thanks for any insight here.


It's more like huge number of files in single folder than the pure size of the 
mails combined. For filesystem based storage formats number of files is always 
a challenge.
In your case mdbox probably would work better as it stores multiple mails in 
single file. The only downside is that it requires periodic purge operations to 
remove deleted mails from middle of the mail bundles.

Sami



Re: What's a Reasonable Inbox Size?

2020-05-07 Thread Asai




We rotate the folder to another name with the date like INBOX-2020-05-07
with instructions how to refresh their folder list (or even modify the
.subscription file for the).

We also cull Trash, deleted items, and spam folders automatically as well.

Regards,
KAM


That makes sense.  So you're saying that very large inboxes are 
generally bad for mobile devices?  How are they bad for the servers?


Asai



Re: [External] Re: What's a Reasonable Inbox Size?

2020-05-07 Thread Kevin A. McGrail
On 5/7/2020 12:43 PM, Asai wrote:
> Thanks for your response,
>
> So, how do those rotation scripts work in concept?
>
> People are still able to access their old inboxes, but it just moves
> them to an archived state?

We rotate the folder to another name with the date like INBOX-2020-05-07
with instructions how to refresh their folder list (or even modify the
.subscription file for the).

We also cull Trash, deleted items, and spam folders automatically as well.

Regards,
KAM


Re: What's a Reasonable Inbox Size?

2020-05-07 Thread Asai

Thanks for your response,

So, how do those rotation scripts work in concept?

People are still able to access their old inboxes, but it just moves 
them to an archived state?


On 5/7/2020 9:40 AM, Kevin A. McGrail wrote:

On 5/7/2020 11:39 AM, Asai wrote:

What's a reasonable inbox size?  Is 20+ GB reasonable and nothing to
worry about?


Great question.

At my firm, we wrote rotation tools that work for mbox format to rotate
inboxes monthly if they are over a certain size.  We also do the sent
items folders.

We find that large inboxes are bad for the server and bad for the client
because the MUAs just don't handle it well either.  1 or 2GBs and you
start to see issues.

After a little bit of user training, they like it.  Part of the routine
maintenance they need.

Regards,
KAM




Re: [External] What's a Reasonable Inbox Size?

2020-05-07 Thread Kevin A. McGrail
On 5/7/2020 11:39 AM, Asai wrote:
> What's a reasonable inbox size?  Is 20+ GB reasonable and nothing to
> worry about?
>
Great question.

At my firm, we wrote rotation tools that work for mbox format to rotate
inboxes monthly if they are over a certain size.  We also do the sent
items folders.

We find that large inboxes are bad for the server and bad for the client
because the MUAs just don't handle it well either.  1 or 2GBs and you
start to see issues.

After a little bit of user training, they like it.  Part of the routine
maintenance they need.

Regards,
KAM




What's a Reasonable Inbox Size?

2020-05-07 Thread Asai

Greetings,

I have several users who have inboxes that are over 20 GB.

Lately I have noticed Dovecot logs say it's taking over 30 seconds to 
sync their mailboxes.


As email admins,  how do you handle inboxes that are so large? Do you 
use mailbox types that have better performance like dbox? We're using 
maildir.


What's a reasonable inbox size?  Is 20+ GB reasonable and nothing to 
worry about?


Thanks for any insight here.

--
Asai7