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General Lab Info (Mainly for Devs)


Lab Infrastructure Services

Misc Admin Tasks
These are infrequently completed tasks that don't fit under any specific service

Production Services

RHEV = Sepia RHE instance
Baremetal = Host in Sepia lab

The Attic/Legacy Info



There are a few CephFS file systems available in the sepia lab. These reside on the Long Running Cluster.

Access to this Ceph cluster is available for any machine on the sepia VPN. You can and should mount these file systems on your laptop or development machine. This reduces load on some shared machines, like teuthology, and usually provides faster access depending on your client or network. However, for everyday use, you may prefer to access CephFS from a machine co-located with the other lab infrastructure, such as senta{01..04} or vossi{01..06}, where OSD latency/bandwidth will be optimal.

In the scripts/commands below, we will ssh to the machine. When given access to the sepia VPN, the ssh key you shared should allow accessing this machine.


On your development machine or laptop, get access to CephFS with the LRC ceph.conf and client.sepian credential:

sudo mkdir -p -m 755 /etc/ceph
ssh 'env CEPH_KEYRING=/etc/ceph/client.sepian.keyring ceph --id sepian config generate-minimal-conf' | sudo tee /etc/ceph/ceph.conf
sudo chmod 644 /etc/ceph/ceph.conf
ssh 'cat /etc/ceph/client.sepian.keyring' | sudo tee /etc/ceph/client.sepian.keyring
sudo chmod 644 /etc/ceph/client.sepian.keyring
ssh 'ceph-authtool /etc/ceph/client.sepian.keyring -n client.sepian -p' | sudo tee /etc/ceph/client.sepian.secret
sudo chmod 600 /etc/ceph/client.sepian.secret

The client.sepian credential is suitable for all Ceph developers to access appropriate LRC resources. In particular, it gives access to the teuthology, scratch, and postfile CephFS file systems.

Mounting all Sepia CephFS file systems

Generate mounts for your /etc/fstab using the script below. Copy it locally, mark it executable, and run:

function genmount {
  local secret=$(sudo cat /etc/ceph/client.sepian.secret)
  # create mountpoint
  sudo mkdir -p -- "$2"
  # make the mountpoint directory (shadowed) unwriteable to prevent accidental modification
  sudo chmod 000 -- "$2"
  # set it immutable to enforce that even for root
  sudo chattr +i -- "$2"
  printf ',,\t%s\tceph\tname=sepian,secret=%s,mds_namespace=%s,_netdev\t0\t2\n' "$1" "$2" "$secret" "$3"
genmount /teuthology-archive /teuthology teuthology | sudo tee -a /etc/fstab
genmount / /scratch scratch | sudo tee -a /etc/fstab
genmount / /postfile postfile | sudo tee -a /etc/fstab

The fstab changes will cause these file systems to mount on boot. After adding these entries for the first time, you need to manually mount them:

sudo mount /teuthology
sudo mount /scratch
sudo mount /postfile

The teuthology FS

The majority of CephFS use is directed at the “teuthology” file system which hosts QA artifacts for analysis. Each test run has a directory in /teuthology-archive. The /etc/fstab file (generated above) has this directory mounted locally at /teuthology:

ls /teuthology/ | head -n 2

It's also common for test artifact paths shared among developers to include a /a/ prefix, such as:


You can generate this helper link using:

ln -s /teuthology /a

The scratch FS

This is a general purpose file system for “scratch” space. Do what you want with it but consider all data in it as eligible for deletion at any time. You're encouraged to create a personal top-level directory.

The postfile FS

The ceph-post-file utility dumps results in this file system. Users are encouraged to use this utility to share artifacts with Ceph developers.

The home FS

There is a “home” file system which hosts the home directories of users of teuthology and potentially other development nodes. Its access is restricted to administrators.

services/cephfs.txt · Last modified: 2023/09/07 18:51 by pdonnell