18289: Documentation changes to reflect we support both Slurm and LSF.

[arvados.git] / doc / install / singularity.html.textile.liquid

diff --git a/doc/install/singularity.html.textile.liquid b/doc/install/singularity.html.textile.liquid
index 1f382539589e588786893bad334bf4491a843da5..dfe12f314a5b681dc343704e6d39e8acec3a1760 100644 (file)
--- a/doc/install/singularity.html.textile.liquid
+++ b/doc/install/singularity.html.textile.liquid
@@ -9,22 +9,17 @@ Copyright (C) The Arvados Authors. All rights reserved.
 SPDX-License-Identifier: CC-BY-SA-3.0
 {% endcomment %}
 
-Arvados can be configured to use "Singularity":https://sylabs.io/singularity/ instead of Docker to execute containers on cloud nodes or a SLURM/LSF cluster. Singularity may be preferable due to its simpler installation and lack of long-running daemon process and special system users/groups.
+h2(#overview). Overview
 
-Please note:
-* *Singularity support is currently considered experimental.*
-* Even when using the singularity runtime, users' container images are expected to be saved in Docker format using @arv keep docker@. Arvados converts the Docker image to Singularity format (@.sif@) at runtime as needed. Specifying a @.sif@ file as an image when submitting a container request is not yet supported.
-* Singularity does not limit the amount of memory available in a container. Each container will have access to all memory on the host where it runs, unless memory use is restricted by SLURM/LSF.
-* Programs running in containers may behave differently due to differences between Singularity and Docker.
-** The root (image) filesystem is read-only in a Singularity container. Programs that attempt to write outside a designated output or temporary directory are likely to fail.
-** The Docker ENTRYPOINT instruction is ignored.
-* Arvados is currently tested with Singularity version 3.5.2.
+Please refer to the "Singularity":{{site.baseurl}}/architecture/singularity.html documentation in the Architecture section.
 
-To use singularity, first make sure "Singularity is installed":https://sylabs.io/guides/3.5/user-guide/quick_start.html on your cloud worker image or SLURM/LSF compute nodes as applicable. Note @squashfs-tools@ is required.
+h2(#configuration). Configuration
+
+To use singularity, first make sure "Singularity is installed":https://sylabs.io/guides/3.7/user-guide/quick_start.html on your cloud worker image or Slurm/LSF compute nodes as applicable. Note @squashfs-tools@ is required.
 
 <notextile>
 <pre><code>$ <span class="userinput">singularity version</span>
-3.5.2
+3.7.4
 $ <span class="userinput">mksquashfs -version</span>
 mksquashfs version 4.3-git (2014/06/09)
 [...]
@@ -34,9 +29,13 @@ mksquashfs version 4.3-git (2014/06/09)
 Then update @Containers.RuntimeEngine@ in your cluster configuration:
 
 <notextile>
-<pre><code>      # Container runtime: "docker" (default) or "singularity" (experimental)
+<pre><code>      # Container runtime: "docker" (default) or "singularity"
       RuntimeEngine: singularity
 </code></pre>
 </notextile>
 
 Restart your dispatcher (@crunch-dispatch-slurm@, @arvados-dispatch-cloud@, or @arvados-dispatch-lsf@) after updating your configuration file.
+
+h2(#singularity_configuration). Singularity configuration
+
+Docker images are converted on the fly by @mksquashfs@, which can consume a considerable amount of RAM. The RAM usage of mksquashfs can be restricted in @/etc/singularity/singularity.conf@ with a line like @mksquashfs mem = 512M@. The amount of memory made available for mksquashfs should be configured lower than the smallest amount of memory requested by a container on the cluster to avoid the conversion being killed for using too much memory.