sporc

Research Computing at Rochester Institute of Technology · Internal RC ceph deployment · Fully Reproducible

System Purpose

Question asked

Please describe the purpose and general usage of the submitted system.  This would include the types of typical applications it supports (e.g., defense applications, molecular dynamics, benchmarking, system test, systems research), and the general use and purpose of the data generated by the applications running on it.

This storage system is the primary storage for Research Computing at Rochester Institute of Technology.   The workload is across numerous domains and from academic to pure research.

The majority of these publications have leveraged this storage system.

https://mirrors.rit.edu/publications/

Availability

Question asked

Please provide the deployment timeframe of the submitted system, or for on-demand cloud systems, the general period over which it is deployed and destroyed.

Please describe the availability of the system to users and who are its set of most regular users.

This ceph cluster has been running for around 7 years, with three main hardware updates and continuous software updates.

It directly supports not only HPC cluster users, but several academic labs, generic file shares, cold storage, direct host storage and virtual machines.

Storage System Software

Question asked

How is this storage software available? (e.g., commercially, open-source, not publicly available) Note that if the storage software is not open-source or commercially available, then a general description would be requested, but this would limit the submission’s reproducibility score.

Can anyone download/purchase this software?

List either product webpage or open-source repo of the exact software used in IO500.

Give any and all additional details of this specific storage deployment: (e.g., type of storage server product such IBM ESS or DDN SFA400X2, use of Ext4 or some other file system on each storage node, dual connected storage media to storage servers).

This storage cluster is built with 100% open source software and "generic" servers / networking.     The OS is redhat, the storage is community ceph, the network is mellanox / nvidia.  

https://www.redhat.com

https://www.ceph.io

https://www.nvidia.com/en-us/networking/

https://www.supermicro.com

Runtime Environment

Question asked

State here that you provided all scripts/documentation that would allow someone else to reproduce your environment and attempt to achieve a similar IO500 score as the submitted system.

NOTE: provide all files/documentation/scripts that would enable a user to build your environment and deploy the custom scripts, software, or config files once they have obtained the appropriate storage system hardware and software. These may be included into the io500.tgz or into the extraCodes upload on the submission form.

Several examples include:

  • Commands used to set striping information (either for the entire system or for particular directories)
  • File system config and tuning information (or a reason why this is not available due to lack of root access, etc) on each node type (e.g., non-default config parameters on all three types of Lustre nodes: MDS, OSS, and client)
  • Any additional scripts utilized that impact IO500 execution beyond the io500 config file. For example, with IBM Spectrum Scale, the output of mmlsconfig, mmlscluster, mmlsfs, and mmlsfileset commands (and possibly even a dump of the configuration if possible). Each file system probably has similar type of config/tuning information that would need to be shared for a user to fully reproduce the environment.

No special tuning was used for this result.  Standard ceph crush maps /  3x replica pools.

Fault Tolerance Mechanisms

Question asked

Does your system have a single point of failure as defined by “Definition 7” of a Production System? Please describe all mechanisms that provide fault tolerance for the submitted storage system. Be specific to your submission, not general storage system capabilities.

  • Power (For example, can power failure of a node or rack bring down the storage system?)
  • Networking (For example, can failure of a single NIC bring down the storage system? Remember that any networking failure that brings down multiple nodes is acceptable)
  • Inter storage data and metadata server (For example, what type of data protection mechanism does the storage system use to keep operating during node failures, e.g., active-active servers, client-directed RAID, declustered RAID, erasure-coding, 3-way replication)
  • Intra storage data and metadata server storage media (For example, how does the storage eysstem protect against fiailure of a single storage device within a node, e.g., raid5)

Please list any additional information needed to determine whether this system has a single point of failure.

There are no known single points of failure in the system as a whole.

Power is UPS/Generator backed with A/B rails feeding redundant power supplies.

This run has each node with a single 100GbE network connection while we wait for POs to be filled for the redundant 400g links.  The frontnet is one vlan and the backnet is a separate vlan.  Our final configuration brings us back to a state where we have Frontnet and Backnet being a bonded standby for the other.  The current lack of individual node network redundancy is covered by ceph replication / failover

Storage and metadata are 3x replica.  The crush map assures data is distributed across nodes.

Execution

Question asked

Please provide a description of how the IO500 benchmark was executed, e.g., via system scheduler (e.g., SLURM) to run a job on the compute cluster, which initially ran a setup process to configure the client and file system, and then started the full benchmark.

During the IO500 benchmark execution was the system entirely dedicated to running the benchmark or were there other jobs running in the same cluster and storage system?

I simply set the directory, made sure the io500 script called srun, and submitted with sbatch to slurm.   Supporting software (e.g. mpi) was loaded via spack.

This run was done in-situ with all services still running 100%.  For testing, I set up a separate cephfs filesystem so the load would be on a dedicated MDS server as not to impact current users.  The testing directory is backed by 100% NVMe drives that are shared with 7 filesystem metadata tiers.  

Caching

Question asked

Please describe all caching mechanisms in client/server that were utilized during the IO500 run. This could include caching in any storage medium (e.g., SSD, RAM).

A few examples would include:

  • Client data/metadata caching (in Linux page cache or in other memory cache)
  • Client side NVMe read-only data cache
  • Storage server metadata/data caching in RAM
  • Storage controller caching
  • RAID card caching

Caching was limited to "standard'' linux kernel filesystem caching.  All drive caches are disabled.

Data Source

Question asked

Is the submitted system a stand-alone storage system or an acceleration layer in front of another storage system that is the source of truth for all application data? This question relates to whether the submitted system is a burst buffer layered on primary storage or primary storage itself.

This is a stand-alone storage system.  No burst buffers were used or harmed in the making of this benchmark result.

Trust

Question asked

Please describe any steps taken to ensure that the results are trustworthy.

  • Did you run the benchmark multiple times and get similar scores?
  • Did you validate the score is below the physical capabilities of the deployed hardware?
  • How did you validate that the storage system follows the IO500 rules regarding persistence, which states, "All data must be written to persistent storage within the measured time for the individual benchmark, e.g. if a file system caches data, it must ensure that data is persistently stored before acknowledging the close"?

I run io500 before and after every maintence window to verify the performance of the HPC and storage environments.  These numbers are consistent with this hardware revision of our cluster.