Unified Lustre mount point

Issue at hand

  • Lustre mount point names (/hera, /lustre/nyx, /lustre/hebe) are changing when decommissioning a Lustre file system.
  • As a consequence, software frameworks need to be modified and adapted: change the path everywhere.
  • Repeats with each decommission.

Goal

Provide a unified and lasting mount point /lustre.

Current situation

Two Lustre file systems are currently in operation: /lustre/hebe and /lustre/nyx.

Approach

  • Mount /lustre/hebe as /lustre
  • Keep /lustre/nyx: make it a subdirectory of /lustre (aka Hebe)
  • HPC copies all data Nyx -> Hebe
  • Finally, replace /lustre/nyx/* with symbolic links

Example: Nyx directory of CBM

  • Copy /lustre/nyx/cbm to /lustre/cbm
  • Downtime / maintenance window + final rsync: only for CBM
  • Move old CBM directory /lustre/nyx/cbm out of the way.
  • Create symbolic link /lustre/nyx/cbm -> /lustre/cbm
  • Go back online for CBM

At this point:

  • CBM data in /lustre/cbm (as well as /lustre/nyx/cbm)
  • All others: data in /lustre/nyx/*

Repeat for all top-level directories aka group-wise

  • thumbs-up All data transfered to Hebe (now /lustre)
  • Paths /lustre/nyx/* remain for backward compatibility
  • Nyx filesystem and servers to be decomissioned

Hebe 2019

  • The path /lustre/hebe is already in use
    • right create symlink /lustre/hebe
  • Some directories presently under /lustre/hebe have the same name as under /lustre/nyx
    • right find individual solutions: renaming / combining

Hebe directories of 09.2018

afseg 0
alice 102T
asteg 0
bhs 3.2G
fn 9.6T
fopi 29T
hades 7T
mbs 3.5T
pbar 2.2T
rz 20T

-- ThomasRoth - 2018-09-12
Topic attachments
I Attachment Action Size Date Who Comment
beamer_UmzugLustre.pdfpdf beamer_UmzugLustre.pdf manage 118.3 K 2019-03-04 - 11:42 ThomasRoth Unified Lustre mount point
Topic revision: r8 - 2019-04-17, ChristopherHuhn