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IMAP at FNAL. Jack Schmidt FNAL Disgruntled Postmaster Hepix April, 1999. Initial Design (low cost). Software Netscape Messenger for NT Hardware Dual 200MHz Pentium Pro with 192Mb of memory Server software and mail files located on a 20GB Software RAID 5 disk array
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IMAP at FNAL Jack Schmidt FNAL Disgruntled Postmaster Hepix April, 1999
Initial Design (low cost) • Software • Netscape Messenger for NT • Hardware • Dual 200MHz Pentium Pro with 192Mb of memory • Server software and mail files located on a 20GB Software RAID 5 disk array • Identical computer system available as hot backup
Problems • Performance • Delays accessing user’s Inbox • Delays foldering mail • Delays in mail delivery • Quotas • shared messages • problems restoring after disk loss • no warning mechanisms
Problems (cont) • Misc- • Corrupted spool area • Only on high activity days • Forwarding • No tools for diagnosing problems • Poor support from Netscape
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 Defragmentation • Balance users across disks. • Limit users to ~ 600 per current server configuration • Stop and Restart service nightly
Solutions (?) • Quotas • disable shared messages • wrote warning program • modified user WEB interface to reflect quota information • Misc • Applied NT4 SP4 • Removed user’s ability to set forwarding
Tools • Perl scripts for: • adding users • moving users • quota management • warning messages • qouta available on User web page • connected users • user 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!
Client Issues • Early versions of Netscape poorly written • User education • keep folders and Inbox small • stick 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
Sharing the Blame • Us • Initial system design • Should have spoke with other sites • Tried being cutting edge • Assumed it would be as easy to manage as our pop server • Netscape • poor support • poor design- separate file for each message • poor documentation • some things work differently than expected
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
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
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