f

IMAP at FNAL

Jack Schmidt

FNAL Disgruntled Postmaster

Hepix April, 1999

f

Initial Design (low cost)

SoftwareNetscape Messenger for NT

HardwareDual 200MHz Pentium Pro with 192Mb of memoryServer software and mail files located on a 20GB

Software RAID 5 disk array Identical computer system available as hot backup

f

Problems Performance

Delays accessing user’s InboxDelays foldering mailDelays in mail delivery

Quotasshared messages

problems restoring after disk loss

no warning mechanisms

f

Problems (cont) Misc-

Corrupted spool area Only on high activity days

ForwardingNo tools for diagnosing problemsPoor support from Netscape

f

Solutions (?) Performance

Brought 2nd server on line faster controllers and disks

RAID 1 instead of RAID 5 still software RAID

separate User storage from Mail server software Disk DefragmentationBalance users across disks.Limit users to ~ 600 per current server configurationStop and Restart service nightly

f

Solutions (?) Quotas

disable shared messageswrote warning programmodified user WEB interface to reflect quota

information Misc

Applied NT4 SP4 Removed user’s ability to set forwarding

f

Tools Perl scripts for:

adding usersmoving usersquota management

warning messages qouta available on User web page

connected usersuser activity (who gets all that mail?)

Freeware program examines threads PMDF software for moving users between servers mailstone program for load testing

Just started working with this!

f

Client Issues Early versions of Netscape poorly written User education

keep folders and Inbox smallstick with one client

Different errors for same problem. Netscape problems with corrupted mail. Outgoing SMTP server incorrectly set. Cache corruption. Need to cleanup in both

Netscape and Outlook Express

f

Sharing the Blame Us

Initial system designShould have spoke with other sitesTried being cutting edgeAssumed it would be as easy to manage as our pop server

Netscape poor supportpoor design- separate file for each messagepoor documentationsome things work differently than expected

f

Immediate Future IMAPserver1 652 users, 318 active IMAPserver2 388 users, 167 active 24% of mail inbound through our gateway is for

IMAP! 36% of data transferred through our gateway is

for IMAP! Need to shut off VAXes at D0 & CDF

Begin move in June, done by September Finish moving Quickmail users

f

Immediate Future Continue with Netscape software Buy true NT server:

4 processors 2GB memory multiple busses high-speed RAID controllers Use RAID 0+1 high-speed disks

f

Central Mail Server Central mail systems for all users to read mail Cluster technology -allows system maintenance

with no/little effect to the user Waiting to see what Sun/Netscape offers

SIMS looks promising Possible blackbox solution?

www.mirapoint.com