Lem

Wroclaw Centre for Networking and Supercomputing · Huawei/xFusion Lustre PD · 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.

The submitted system is a long-term storage system at our HPC center available for all users. The main purpose of this system is to store users’ large data sets containing input and output data that is directly processed during the computations.

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 system is available on all computing nodes and on the main access node. Our users are academics and researchers from different fields of science and industry affiliated at universities and research institutes.

The submitted system was deployed on September 2024 on the production servers but has not been made available to most of our users yet (only for the selected groups). In general, the submitted storage system will be available to all users of our supercomputer, which obtained access to the supercomputer via their HPC services (i.e. computational grants). In particular, each HPC service at our site has a private directory at the submitted Lustre filesystem, with blocks and inodes quota set according to the service needs (specified during the application procedure).

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).

The Lustre filesystem is open-source and publicly available.

The submitted storage system is composed of 8 OSS servers and 2 MDS servers. The 8 OSS servers share 5 Huawei Oceanstore 5510 arrays and both MDS servers share one Huawei Dorado 6000 V6 array.

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.

IO500 was compiled using OpenMPI/5.0.3-GCC-13.3.0 (built with EasyBuild software) without any additional compilation flags and on the server with the same architecture as benchmark client nodes (compilation followed the README.md from the git source).

Installed Lustre packages (from the official Lustre repository): lustre-client-2.15.5-1.el9.x86_64.rpm and lustre-client-dkms-2.15.5-1.el9.noarch.rpm

Different file striping options were utilized for particular main test directories:
- ior-easy: DoM up to the first 1MB, further striped across 8 OSTs with 4M stripe size (`lfs setstripe -L mdt -E 1M -E -1 -S 4M -c 8`)
- ior-hard, mdtest-easy, mdtest-hard: DoM up to the first 1MB, further striped across all available OSTs (i.e. 50) with 4M stripe size (`lfs setstripe -L mdt -E 1M -E -1 -S 4M -c -1`)

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.

- Power: redundant power available
- Networking: 2-level IB fat-tree, two links per MDS/OSS, one link per client node
- MDS and OSS have 2 infiniband ports (multi-rail on). Each MDS and OSS server in a failover pair (MDT/OSTs can transfer to other MDS/OSS on failure).
- HDD and SSDs are in a RAID configurations to mitigate failures.

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?

The IO500 test was run on 10 client nodes via the SLURM job: nodes were made exclusive for the job (i.e. no other users’ jobs run at these nodes), all CPU cores and all available memory were allocated on the nodes (but the later test utilized smaller amount of CPU threads as denoted in the configuration of the test).

No other users were using the submitted Lustre filesystem at the time of the test.

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

No additional client and server caching was utilized during the tests.

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.

The submitted filesystem is a stand-alone storage system that is directly accessed.

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"?

The tests were run several times, also using different configurations (with varied numbers of threads per node and striping).
The obtained results met the hardware capabilities and were below the physical capabilities of network and storage devices.