19054: doc update

Arvados-DCO-1.1-Signed-off-by: Ward Vandewege <ward@curii.com>

diff --git a/doc/install/crunch2-cloud/install-dispatch-cloud.html.textile.liquid b/doc/install/crunch2-cloud/install-dispatch-cloud.html.textile.liquid
index 0ed7a599fc79df23528e78fd0691d9a14c2bf0d7..3efd49fd141f17e6e9b5a55a2097ba16741dd368 100644 (file)
--- a/doc/install/crunch2-cloud/install-dispatch-cloud.html.textile.liquid
+++ b/doc/install/crunch2-cloud/install-dispatch-cloud.html.textile.liquid
@@ -74,7 +74,7 @@ Add or update the following portions of your cluster configuration file, @config
 </code></pre>
 </notextile>
 
-h4(#GPUsupport). NVIDIA GPU support
+h3(#GPUsupport). NVIDIA GPU support
 
 To specify instance types with NVIDIA GPUs, you must include an additional @CUDA@ section:
 
@@ -95,7 +95,15 @@ To specify instance types with NVIDIA GPUs, you must include an additional @CUDA
 
 The @DriverVersion@ is the version of the CUDA toolkit installed in your compute image (in X.Y format, do not include the patchlevel).  The @HardwareCapability@ is the CUDA compute capability of the GPUs available for this instance type.  The @DeviceCount@ is the number of GPU cores available for this instance type.
 
-h4. Minimal configuration example for Amazon EC2
+h3. AWS Credentials for Local Keepstore on Compute node
+
+When @Containers/LocalKeepBlobBuffersPerVCPU@ is non-zero, the compute node will spin up a local Keepstore service for faster storage access. If Keep is backed by S3, the compute node will need to be able to access the S3 bucket.
+
+If the AWS credentials for S3 access are configured in @config.yml@ (i.e. @Volumes/DriverParameters/AccessKeyID@ and @Volumes/DriverParameters/SecretAccessKey@), these credentials will be made available to the local Keepstore on the compute node to access S3 directly and no further configuration is necessary.
+
+Alternatively, if an IAM role is configured in @config.yml@ (i.e. @Volumes/DriverParameters/IAMRole@), this role (or an equivalent role) needs be configured in the @CloudVMs/DriverParameters/IAMInstanceProfile@ parameter. That way, @arvados-dispatch-cloud@ can attach the appropriate instance profile to the compute node as it starts up and make the role available to the compute node.
+
+h3. Minimal configuration example for Amazon EC2
 
 The <span class="userinput">ImageID</span> value is the compute node image that was built in "the previous section":install-compute-node.html#aws.
 
@@ -146,7 +154,7 @@ Example policy for the IAM role used by the cloud dispatcher:
 </pre>
 </notextile>
 
-h4. Minimal configuration example for Azure
+h3. Minimal configuration example for Azure
 
 Using managed disks: