Move filesystem to new node

Site Administrators
#1

What is the easiest way to migrate an fs to new FST hardware?

Say I have FST1 which is old hardware and will be retired and has FS1 and FS2. I have a newer node I want to swap in. What is the best way to do this?

Should I also name the new node FST1 and simply move the physical disk connection to the new node? Or can I name it FST2 and move the connection? If I do this, will EOS recognize these filesystems as now being on FST2? (I would probably backup /var/eos on the old node and copy it to the new node in either case)

–
Dan Szkola
FNAL

#2

Anyone have a suggestion here? We have two nodes that were retired because we got rid of the disk they were attached to. We want to use these nodes to replace two older nodes that still have disk attached. Should we just bring the newer nodes up with the same name as the two older nodes and swap them in?

#3

Hi Dan,

If your configuration is in QuarkDB, there is a command in eos-config-inspect for relocating a filesystem to a different FST. (eos-config-inspect relocate-filesystem --fsid <target fsid to change> --new-fst-host <..> --new-fst-port <..>, check --help for usage)

The following steps should do the trick:

  1. Setup the new, target FST
  2. Shut down both source and target FSTs
  3. Move the physical hard drives
  4. Run the command
  5. Restart MGM, start source and target FSTs

Note that the command does “surgery” directly in the configuration, so until the MGM is restarted, the changes will not take effect.

A limitation is that the mountpoint path needs to remain the same, I could add the option to change that, too. (We haven’t needed this, yet)

Cheers,
Georgios

#4

Configuring the new nodes with the same hostnames as the old ones should work, too. Just make sure to use the same mountpoint paths for the disks.

Cheers,
Georgios

#5

Hi Georgios,
Our configuration is stored in a file instead of in QuarkDB, so is there any way to convert the configuration format from file to QuarkDB?

#6

Hello,

Andreas informed me this is also implemented as an MGM command: eos fs mv fsid node:port, available from 4.8.5. It doesn’t require restart of the MGM, or configuration in QuarkDB.

I’ll be on holidays from tomorrow, if you need help with the command, please ping @apeters

The procedure to convert from file to QDB configuration will be added to the documentation soon, @esindril will provide you with the link.

Cheers,
Georgios

#7

Hi, you can find instructions on moving to QDB config in the documentation: http://eos-docs.web.cern.ch/eos-docs/configuration/master_quarkdb.html

Cheers,
Georgios