Sepia Lab Wiki

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
====== CephFS ======

There are a few CephFS file systems available in the sepia lab. These reside on the [[services:longrunningcluster|Long Running Cluster]].

Access to this Ceph cluster is available for any machine on the [[:vpnaccess|sepia VPN]]. You can and **should** mount these file systems on your laptop or development machine. This reduces load on some shared machines, like [[services:teuthology|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 a [[:devplayground|Developer Playground]] machine, where OSD latency/bandwidth will be optimal.

In the scripts/commands below, we will ssh to the ''reesi001.front.sepia.ceph.com'' machine. When [[:vpnaccess#requesting_access|given access to the sepia VPN]], the ssh key you shared should allow accessing this machine.


==== Authorization ====

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

<code bash>
sudo mkdir -p -m 755 /etc/ceph
ssh reesi001.front.sepia.ceph.com '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 reesi001.front.sepia.ceph.com 'cat /etc/ceph/client.sepian.keyring' | sudo tee /etc/ceph/client.sepian.keyring
sudo chmod 644 /etc/ceph/client.sepian.keyring
ssh reesi001.front.sepia.ceph.com '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
</code>

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:

<code bash>
#!/bin/bash

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 '172.21.2.201,172.21.2.202,172.21.2.203:%s\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
</code>

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:

<code bash>
sudo mount /teuthology
sudo mount /scratch
sudo mount /postfile
</code>

==== 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'':

<code bash>
ls /teuthology/ | head -n 2
abhi-2019-12-04_08:55:20-rgw-wip-abhi-testing-2019-12-03-1859-distro-basic-smithi
abhi-2019-12-04_17:41:25-rgw-wip-abhi-testing-2019-12-04-1433-distro-basic-smithi
</code>

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

''/a/teuthology-2023-06-10_14\:23\:08-upgrade\:pacific-x-reef-distro-default-smithi/7301152/teuthology.log''

You can generate this helper link using:

<code bash>
sudo ln -s /teuthology /a
</code>

==== 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 [[https://docs.ceph.com/en/latest/man/8/ceph-post-file/|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.
Sepia Lab Wiki

User Tools

Site Tools

Page Tools
