[Dovecot] SSD drives are really fast running Dovecot

[Stan Hoeppner]

Brad Davidson put forth on 1/14/2011 6:25 PM:

> We just bought 252TB of raw disk for about 5k users. Given, this is
> going in to Exchange on Netapp with multi-site database replication, so
> this cooks down to about 53TB of usable space with room for recovery
> databases, defragmentation, archives, etc, but still... 28TB is not much
> anymore.

The average size of an email worldwide today is less than 4KB, less than one
typical filesystem block.

28TB / 4KB = 28,000,000,000,000 bytes / 4096 bytes = 6,835,937,500 =
6.8 billion emails / 5,000 users =
1,367,188 emails per user

6.8 billion emails is "not much anymore" for a 5,000 seat org?

You work for the University of Oregon, correct?

From:  http://sunshinereview.org/index.php/Oregon_state_budget

"Oregon's budget for FY2009-11 totals $61 billion.[1] The state faced a $3.8
billion biennium FY 2010-11 budget deficit, relying heavily on new taxes and
federal stimulus money to close the gap in the final budget signed by Gov. Ted
Kulongoski and passed by the Oregon Legislature.[2][3] In Aug. 2010, however,
the state budget deficit increased and could top $1 billion.[4] As a result, the
governor ordered 9% budget cuts.[5]"

How much did that 252TB NetApp cost the university?  $300k?  $700k?  Just a drop
in the bucket right?  Do you think that was a smart purchasing decision, given
your state's $3.8 Billion deficit?  Ergo, do you think having an "unlimited
email storage policy" is a smart decision, based on your $3.8 Billion deficit?
Your fellow tax payers would probably suggest you need to reign in your email
storage policy.  Wouldn't you agree?

This is why people don't listen to Noel (I've had him kill filed for a year--but
not to the extreme of body filtering him).  They probably won't put much stock
in what you say either Brad.  Why?

You two don't live in reality.  Either that, or the reality you live in is
_VERY_ different from the rest of the sane world.  Policies like U of O's
unlimited email drive multi hundred thousand to million dollar systems and
storage purchases, driving the state budget further into the red, and demanding
more income tax from citizens to pay for it, since Oregon has no sales tax.

"28TB is not much anymore."  Tell your fellow taxpayers what that 252TB cost
them and I guarantee they'll think 28TB is overkill, especially after you tell
them 28TB would store more than 1.3 million emails per each of those 5k
students, faculty, staff, etc.

For comparison, as of Feb 2009, the entire digital online content of the Library
of Congress was only 74TB.  And you just purchased 252TB just for email for a
5,000 head count subsection of a small state university's population?

http://blogs.loc.gov/loc/2009/02/how-big-is-the-library-of-congress/

Sane email retention policies would allow any 5k seat organization to get 10+
years of life out of 28TB (assuming the hardware lived that long).  Most could
do it with 1TB, which would allow 244k emails per user mailbox.  Assuming 28TB
net, not raw.  Subtract 20% for net and you're at 195k emails per user mailbox.
 Still overkill...

-- 
Stan