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--- services:cephfs [2023/06/08 17:05]
pdonnell created
+++ services:cephfs [2024/01/05 20:05] (current)
ljflores Need sudo unless you are running as root.
@@ Line 1: / Line 1: @@
-test
+====== 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.

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