University of Helsinki Department of Computer Science
 

Department of Computer Science

Department information

 
Suomeksi

The CS Department's e-mail system upgrade on January 2nd, 2003

The e-mail system at the Department of Computer Science, University of Helsinki will be upgraded on January 2nd, 2003. The new e-mail servers and software will provide much better performance and new features. This document concerns the following issues:

  1. How does the upgrade affect e-mail usage? [follow]
  2. Which measures are required from the users? [follow]
  3. Usage restrictions during the upgrade [follow]
  4. Technical background [follow]

All e-mail folders on the mail.cs.helsinki.fi server except for the inbox folder are unreachable after the upgrade! Each user can restore his/her folders by following the instruction in the chapter two of this document.

The CS Department's computing facilities staff members provide more information on the e-mail system upgrade either by e-mail or personally.


How does the upgrade affect e-mail usage?

Regardless of the mail system upgrade, some things remain the same:

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Which measures are required from the users?

Inbox is the only folder on the mail.cs.helsinki.fi server which will be automatically transferred to the new system. Each user has to copy all other folders manually with the folders2imap utility if he/she wants to continue using them on the mail server.

It is not mandatory to copy folders to the new server. Old mail folders are not lost but they are stored as ASCII text files in each user's fs home directory, most probably in /home/fs/username/Mail/. You just can't use them through the mail.cs.helsinki.fi server any more if they are not copied there with folders2imap. Folders2imap won't delete the old folder files, it just makes copies of them on the new mail server. You need to archive or delete the obsoleted mail folder files manually if you want to do so.

Folders2imap is available in CS Linux (e.g. the melkki.cs.helsinki.fi server or any fixed CS Linux workstation) with the command folders2imap. It is recommended to start the utility in a terminal window (e.g. Konsole, xterm, rxvt) because the program prints some log information during its operation. If the utility is started on an SSH session in Windows, only text mode user interface is available. So it is recommended to use folders2imap in Linux.

If you use a Linux workstation, please make sure that the Linux system is at least on the update level #2.077. Otherwise folders2imap will not work correctly. You can check the version number in the main login screen [example picture] or with the command "cat /etc/csl-release".

Folders2imap will tell you what you need to do after you have started it. If the transferring of your mail folders is successful, you can archive the old folders with the command

/opt/misc/bin/archive-mailfolders

It will create a file /home/fs/username/oldmailfolders.tar.gz which is a compressed archive of all files that were in /home/fs/username/Mail/. Further, you can delete the archive file or transfer it to a writable CD.

In case of problems or questions please contact the CS Department's computing facilities staff either by e-mail or personally.

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Usage restrictions during the upgrade

The mail.cs.helsinki.fi server is down on January 2nd, 2003, between 9:00 a.m. and 16:00 p.m. E-mail cannot be read during that time. Incoming e-mail messages are received and they are available for reading after the break.

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Technical background

The new server hardware includes one Intel Pentium 4 2.66 GHz processor and 2 GB of memory. 180 GB SCSI disk space has been allocated for e-mail folders. The operating system is CS Linux which is based on RedHat Linux. Actually there are two server hosts each of which is capable of acting as the primary mail server.

We have decided to use the Courier mail server software in the hope of maximum performance. There have been serious problems with the performance of the old UW IMAP server and its mail storage data structures, namely the mbox mail folder format. However, using Courier-IMAP and its maildir structured mail folders requires that each user's all mail folders have to be stored in a single file system. This is why all mail folders need to be transferred to the new mail server if the user wants to continue using then through the server. Previously users' inbox folders were located on the mail server and all other folders on fs. A detailed comparison of the performance of the mbox and maildir folder formats is available in a document associated with the Courier e-mail software. In addition to the new IMAP server software we will use the Courier mailing list manager and the SqWebMail web mail. SqWebMail replaces the previous NeoMail web interface.

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support@cs.helsinki.fi