Archive for the ‘Linux’ Category

Update on Matrix (chat)

Friday, October 9th, 2020

Since our launch of Matrix at the D-PHYS in March a few things have changed.

Important changes

  • The subdomain of the D-PHYS hosted Riot Element Web App changed and is now at element.phys.ethz.ch. If you still use the old subdomain riot.phys.ethz.ch, please move over to the new domain and verify your new session. We will start redirecting the domain in 2021. If you have no other way of getting access to your encryption keys, you could lose access to your encrypted messages
  • New documentation is available at readme.phys.ethz.ch/chat

Other changes

  • Federation with other Matrix instances at ETH and the rest of the Matrix network, giving us access to bridged networks like IRC, Slack, etc. as well
  • We now auto-invite new users to two more ISG moderated rooms (News/Status). Opt-out by leaving if you do not wish to receive updates from us (discouraged!). All existing members of the D-PHYS Lobby have been joined last night
  • End to end encryption support (enabled by default). Element Web does not provide a search function in encrypted rooms as that would be a security issue, use the Desktop App instead
  • Secure key backup method has been set to show one option only (‘Security Passphrase’) to new users, which will still provide the secondary recovery method using a ‘Security Key’
  • We opened up public rooms and room aliases for everyone. Publish your room in the public room directory to be discoverable by others on the Matrix network
  • We enabled quota of 2 GiB (initial) quota per user for media (uploads) to protect from accidental or abusive over-usage
  • Bots for gitlab, reminders, RSS feeds and more
  • Bridges for webhooks and Slack
  • Integrations (widgets)
  • Import of the Slack workspace history of 3 groups at the D-PHYS
  • An Element Web instance with experimental (Labs) features like tags
  • A tag manager to organize many rooms in large accounts
  • Jitsi video conferencing and screen sharing solution (still experimental but used by ISG on a daily basis)
  • URL redirecting service to invite people via websites or email

Lookout

  • We will focus on improving performance and less on features
  • Stabilizing 1:1 calls and video (TURN server) and Jitsi (group calls)

For help and discussion about Matrix and Element join #matrix:phys.ethz.ch

New SSH Host Keys on Managed Linux Machines

Wednesday, August 12th, 2015

After several years it was time to update the SSH host keys of our managed Linux machines. Therefore, if you reconnect with SSH, you might get a warning similar to this one:

ssh login.phys.ethz.ch
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
36:04:d8:3d:89:a2:76:19:ef:b6:f0:0a:f2:5c:81:a3.
Please contact your system administrator.
Add correct host key in ~/.ssh/known_hosts to get rid of this message.
Offending key in ~/.ssh/known_hosts:1
RSA host key for login.phys.ethz.ch has changed and you have requested strict checking.
Host key verification failed.

This is because your computer has memorized the previous host key and is bailing because the current one is different. This mechanism is designed to prevent users from man-in-the-middle attacks. In our case it can be treated as a mere notification that the SSH key has changed.

In order to get rid of this warning, you simply need to delete the old key from your ~/.ssh/known_hosts file. This can be done either by deleting the entry manually or with the following command

ssh-keygen -R login.phys.ethz.ch

for the machine you try to ssh into.

On the next SSH connection you will be prompted to accept the new key. Power users may also download the full list of SSH keys of all our managed Linux computers.

Maintenance downtime for group share and home directory fileservers

Friday, December 19th, 2014

UPDATE 13:30 – Groupdata is back online
UPDATE 02:25 – Astrogate and Windata are back online, except groupdata
UPDATE 22:20 – Home server is back online and email working again

In order to upgrade the operating system on serveral servers, we schedule a maintenance downtime on

Sunday, 4th January 2015, starting at 22:00.

Schedule:

  • 22:15 start working on the home server (mail services disabled, incoming mail will be queued)
  • 22:20 start working on the group share servers (windata & astrogate)
  • ~ 22:45 home directories and mail services should work again
  • ~ 00:00 group shares will incrementally come back during the night
  • During the downtime you can access readonly backups of your data of the night before, take a look at our readme.

    We apologize in advance for any inconvenience this service interruption might cause.

    Computer support during christmas holidays

    Friday, December 19th, 2014

    The ETH Zurich will be officially closed between Wednesday, 24th of December 2014 and Sunday, 4th of January 2015. During this time, we can only provide limited support. Please follow these rules to save us from superfluous work:

    • Switch off printers
    • Switch off your personal workstation and notebook except for the following:
    • Do not switch off our managed Linux workstations.

    We will try to follow our e-mail, but you may also have luck and meet some of us in our IRC channel.

    Server Maintenances this Week: E-Mail and BackupPC

    Tuesday, June 17th, 2014

    We have scheduled a software maintenance of the D-PHYS mail server for tomorrow, Wednesday, the 18th of June 2014, starting in the late afternoon around 5pm. A downtime of all D-PHYS mail services during the evening will be part of the maintenance. The downtime is expected to take approximately 15 to 30 minutes.

    During the downtime sending and receiving e-mails will not be possible and the web mail service will be not available. Incoming mails during the downtime will be delayed.

    Additionally there will be a downtime of our “BackupPC” backup service for laptops and lab PCs due to server relocation on Thursday (19th of June 2014) starting around 9am.

    Computer support during christmas holidays

    Monday, December 23rd, 2013

    The ETH Zurich will be officially closed between Tuesday, 24th of December 2013 and Friday, 3rd of January 2014. During this time, we can only provide limited support. Please follow these rules to save us from superfluous work:

    • Switch off printers
    • Switch off your personal workstation and notebook except for the following:
    • Do not switch off our managed Linux workstations.

    We will try to follow our e-mail, but you may also have luck and meet some of us in our IRC channel.

    Computer support during christmas holidays

    Thursday, December 20th, 2012

    The ETH Zurich will be officially closed between Monday, 24th of December 2012 and Monday, 2nd of January 2013. During this time, we can only provide limited support. Please follow these rules to save us from superfluous work:

    • Switch off printers
    • Switch off your personal workstation and notebook except for the following:
    • Do not switch off our managed Linux workstations.

    We will try to follow our e-mail, but you may also have luck and meet some of us in our IRC channel.

    Maintenance downtime for group share fileserver

    Wednesday, September 5th, 2012

    In order to upgrade the operating system and the server hardware, we schedule a maintenance downtime on

    Wednesday, 12. September 2012, starting at 17:00 and lasting for several hours.

    During this time, you will not have access to the group directories.

    We apologize in advance for any inconvenience this service interruption might cause.

    Migration of Home Directories

    Thursday, December 22nd, 2011

    In order to gain more flexibility and performance, the home directories will move to our new SAN setup.

    This will be done on Thursday, 5. January 2012, between 18:00 and 22:00.

    During this time the home directories (winhome, machome, unixhome), the mail services and some websites will not be available.

    To protect you from losing or corrupting any of your files, we strongly recommend you close all open files on the home directories before the migration.

    Since we have switched to generic names for our services, the home directories will still be accessible the same way as before after the migration is over, so you don’t have to change anything.

    Update, Jan 10: We experience some unexpected and dubious problems with 32bit binaries (and therefore, 32bit machines). The symptoms range from not being able to log in (GNOME and KDE) to acroread and mathematica not starting. Workarounds while we’re working on a solution: for failing logins, please call us. For acroread, use evince instead. For mathematica, log in to a 64bit machine, eg. login.phys, and start it remotely.

    Update, 21:25: The migration is finished and everything should work again! In case of problems please contact the ISG Helpdesk (3 26 68)

    Computer support during christmas holidays

    Thursday, December 22nd, 2011

    The ETH Zurich will be officially closed between Monday, 26th of December 2011 and Monday, 2nd of January 2012. During this time, we can only provide limited support. Please follow these rules to save us from superfluous work:

    • Switch off printers
    • Switch off your personal workstation and notebook except for the following:
    • Do not switch off our managed Linux workstations.

    We will try to follow our e-mail, but you may also have luck and meet some of us in our IRC channel.