Moving home directories to a new file server

All network home directories of Computer Science  Department's users will be moved to the new csfs file server monday 23.4. The home directories will be moved one home directory at a time, so there won't be any long service breaks. When the home directory is being moved there is a short time when it is not available. For small home directories this is just a few seconds, but for some of the largest home directories it will take minutes.

We did our best to avoid moving a home directory, if it was in active use. If your home directory has not yet been moved, it has been constantly in active use for longer than a month. Unfortunately, we cannot wait for the home directory to be inactive anymore. This means that we shall kill all processes accessing the old file servers (which we can find) and move the directories regardless of activity, starting from monday 23.4. So you still have time to close all your processes accessing fs home directories (logging out from all department's hosts, including closing all screen sessions is one good way to do this).

In melkki.cs.helsinki.fi and melkinpaasi.cs.helsinki.fi there is a command wanna-new-home-directory, which you can run to have the transfer faster (in most cases in a few minutes) and to get an email notification of finished transfer.

There are some important configuration changes in the new file server:

  • The most important change is that the new NFS file shares will need kerberos authentication in order to be used in Linux classroom and personal workstation hosts. This will have some important consequences:
    • In Linux hosts you need a personal kerberos ticket to be able to access NFS file shares. This ticket is normally created at login time, but can also be created manually with command kinit. Please see the page on Single sign-on Linux authentication.
    • If you do a remote login to a Linux classroom host with a ssh secret key, you will not get a kerberos ticket and NFS file shares will not work. You need to authenticate with a password, or get a forwardable kerberos ticket. Department's Linux hosts create and forward kerberos tickets by default.
    • Kerberos tickets can only be obtained against your department's master password. If you login to a office computer with a local user account with a password which is different from department's master password, you will not get a kerberos ticket. Easiest and most convenient fix is to just use the same master password also in personal workstations.
  • Readable and writeable NFS shares without kerberos authentication will still be available in interactive Linux servers like melkki, melkinpaasi, staff, users and Ukko cluster.  In these hosts everything should work exactly as before, including remote logins using ssh secret keys.
  • The old home directory paths /home/fs/<login> and /fs/home/<login>  will continue to work as before.
  • Your new Linux home directory will be /cs/fs/home/<login>. In Windows the path will be \\csfs\<login>.
  • The old physical home directory path /fs-X/Y/<login> will not work anymore after the home directory is moved.
  • The group directories have already been using kerberos authentication on the same server csfs since year 2011. If you can access group files, you should have no problems accessing your fs home on the new server.
  • In the new server the default disk quota  is 10 gibibytes and hard quota limit will be 40 gibibytes. For staff members the default quota is 30 gibibytes and hard quota limit is 100 gibibytes. One gibibyte is 10243 bytes. Please remember that if everyone uses their full disk quota, we will run out of disk space.

 

13.04.2012 - 10:53 Jani Jaakkola
16.02.2012 - 14:30 Jani Jaakkola