_index.md

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title = "HCC Documentation"
description = "HCC Documentation Home"
weight = "1"
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HCC Documentation
============================


The Holland Computing Center supports a diverse collection of research
computing hardware.  Anyone in the University of Nebraska system is
welcome to apply for an account on HCC machines.

Access to these resources is by default shared with the rest of the user
community via various job schedulers. These policies may be found on the
pages for the various resources. Alternatively, a user may buy into an
existing resource, acquiring 'priority access'. Finally, several
machines are available via Condor for opportunistic use. This will allow
users almost immediate access, but the job is subject to preemption.

#### [New Users Sign Up](http://hcc.unl.edu/new-user-request)

#### [Quick Start Guides](/Quickstarts)

Which Cluster to Use?
---------------------

**Crane**: Crane is the newest and most powerful HCC resource . If you
are new to using HCC resources, Crane is the recommended cluster to use
initially.  Limitations: Crane has only 2 CPU/16 cores and 64GB RAM per
node. CraneOPA has 2 CPU/36 cores with a maximum of 512GB RAM per node.

**Rhino**: Rhino is intended for large memory (RAM) computing needs.
Rhino has 4 AMD Interlagos CPUs (64 cores) per node, with either 192GB or 256GB RAM per
node in the default partition. For extremely large RAM needs, there is also
a 'highmem' partition with 2 x 512GB and 2 x 1TB nodes.

User Login
----------

For Windows users, please refer to this link [For Windows Users]({{< relref "for_windows_users" >}}).
For Mac or Linux users, please refer to this link [For Mac/Linux Users]({{< relref "for_maclinux_users">}}).

**Logging into Crane or Rhino**

{{< highlight bash >}}
ssh <username>@crane.unl.edu
{{< /highlight >}}

or

{{< highlight bash >}}
ssh <username>@rhino.unl.edu
{{< /highlight >}}

Duo Security
------------

Duo two-factor authentication is **required** for access to HCC
resources. Registration and usage of Duo security can be found in this
section: [Setting up and using Duo]({{< relref "/Accounts/setting_up_and_using_duo">}})

**Important Notes**

-   The Crane and Rhino clusters are separate. But, they are
    similar enough that submission scripts on whichever one will work on
    another, and vice versa (excluding GPU resources and some combinations of
    RAM/core requests).
     
-   The worker nodes cannot write to the `/home` directories. You must
    use your `/work` directory for processing in your job. You may
    access your work directory by using the command:
{{< highlight bash >}}
$ cd $WORK
{{< /highlight >}}

Resources
---------

- ##### Crane - HCC's newest machine, Crane has 7232 Intel Xeon cores in 452 nodes with 64GB RAM per node.

- ##### Rhino - HCC's AMD-based cluster, intended for large RAM computing needs.

- ##### Red - This cluster is the resource for UNL's [USCMS](https://uscms.org/) Tier-2 site.

- ##### Anvil - HCC's cloud computing cluster based on Openstack

- ##### Glidein - A gateway to running jobs on the OSG, a collection of computing resources across the US.

Resource Capabilities
---------------------

| Cluster | Overview | Processors | RAM | Connection | Storage
| ------- | ---------| ---------- | --- | ---------- | ------
| **Crane**   | 548 node Production-mode LINUX cluster | 452 Intel Xeon E5-2670 2.60GHz 2 CPU/16 cores per node<br> <br>116 Intel Xeon E5-2697 v4 2.3GHz, 2 CPU/36 cores per node<br><br>("CraneOPA") | 452 nodes @ \*64GB<br><br>79 nodes @ \*\*\*256GB<br><br>37 nodes @ \*\*\*\*512GB | QDR Infiniband<br><br>EDR Omni-Path Architecture | ~1.8 TB local scratch per node<br><br>~4 TB local scratch per node<br><br>~1452 TB shared Lustre storage
| **Rhino** | 110 node Production-mode LINUX cluster | 110 AMD Interlagos CPUs (6272 / 6376), 4 CPU/64 cores per node | 106 nodes @ 192GB\*\*/256GB\*\*\* <br><br> 2 nodes @ 512GB\*\*\*\* <br><br> 2 nodes @ 1024GB\*\*\*\*\* | QDR Infiniband | ~1.5TB local scratch per node <br><br> ~360TB shared BeeGFS storage |
| **Red** | 344 node Production-mode LINUX cluster | Various Xeon and  Opteron processors 7,280 cores maximum, actual number of job slots depends on RAM usage | 1.5-4GB RAM per job slot | 1Gb, 10Gb, and 40Gb Ethernet | ~10.8PB of raw storage space |
| **Anvil** | 76 Compute nodes (Partially used for cloud, the rest used for general computing), 12 Storage nodes, 2 Network nodes Openstack cloud | 76 Intel Xeon E5-2650 v3 2.30GHz 2 CPU/20 cores per node | 76 nodes @ 256GB | 10Gb Ethernet | 528 TB Ceph shared storage (349TB available now) |

You may only request the following amount of RAM: <br>
\*62.5GB <br>
\*\*187.5GB <br>
\*\*\*250GB <br>
\*\*\*\*500GB <br>
\*\*\*\*\*1000GB