Stash runs on Ceph, a highly-scalable, clustered, POSIX-compliant network filesystem. You may use this feature for temporary data storage.
This page will introduce users to accessing data stored on stash remotely using HTTP and XRootD.
After you login to login-el7.uscms.org, you can access your stash area as followed:
Stash is mounted on the CMS Connect login node (
/stash, and is accessible to workers via XRootD. The portion of your Stash designated public is also available directly via HTTP.
Accessing Stash via XrootD
You can access your stash work area via XRootD using the following server:
Use xrdcp to copy your data. For example, to copy the previous file from a worker node:
Copying to stash via XRootD
To transfer data to /stash via XRootD, a user needs to create a directory in its stash area with 777 permissions on the CMS Connect login node first (permissions can be changed afterwards). E.g:
Then, xrdcp can be user from a remote machine to the XRootD stash server.
Accessing Stash via HTTP
User accounts on CMS Connect have a directory that is automatically web accessible via
http://stash.osgconnect.net/+username . This directory is located at /stash2/user/username/public. To make a file or directory accessible, copy it to this directory or a subdirectory of this directory and give files permissions of 644 and directories permissions of 755. E.g. :
Copying files via HTTP
You can download your files using wget easily:
You can also use curl, for example:
Using OSG stashcp
OSG provides a utility to copy files coming from /stash.
To load the tool, you can do
Using stashcp and XrootD from OSG TensorFlow containers
Please, follow this link for instructions regarding copying data inside the containers via XrootD or Stashcp.