Dell Lightning Filesystem

Dell Technologies · Dell Technologies Dell Lightning Filesystem · 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 uses Dell Lightning Filesystem (DLFS), a parallel filesystem designed from the ground up for AI (large-scale training, memory-intensive inferencing) and HPC workloads

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.

We expect to be using this configuration for validating AI and HPC applications, GPU-accelerated or otherwise, with DLFS to make sure that interoperability and performance are second to none. Dell in this context happens to be using this DLFS deployment for solution level assessment.

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 storage system software used is Dell Lightning Filesystem v1 (DLFS). It is commercially available since April 2026.

It can be purchased from the Dell website : https://www.dell.com/en-us/shop/storage-servers-and-networking-for-business/sf/lightning-file-system

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.

The IO500 test environment is fully reproducible. It utilizes general-purpose servers.

10 clients were used in this "10 Node Production Challenge"                                                                 

Single socket AMD EPYC 9845 160-Core Processor                                                     

768 GB of memory                                                 

3x 400 GbE network                                               

Rocky Linux 9.6

IO500 benchmark was executed using OpenMPI 4.6.1 (built from source without changes)

DLFS was deployed by using standard installation steps that came with the product.

Regarding mount option:

According to PFS export expressed on the Lightning cluster side, the Lightning PFS will be auto mounted on the clients that it has been exported to. There is no mount option customers need to use to reproduce the submitted performance numbers

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.

The infrastructure has redundant power

DLFS uses data protection of mapped RAID-60 over the server nodes, so it tolerates the loss of up to two nodes, or the loss of any number of devices on up to two nodes.

Network fault tolerance (multipath) with support for up to 3 NICs per client and server node, which tolerates the loss of up to two network paths.

Server node failover, allowing the server cluster to recover from the failure of a node provided at least four healthy nodes survive (four, because RAID-60 is dual fault tolerant).  No data loss occurs when server failure is handled by failover.

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?

Executed by mpirun jobs from the primary client across 10 clients and a hostfile.

The mpirun args used:

"--map-by ppr:128:node --mca pml ucx --mca btl ^openib -x UCX_NET_DEVICES=mlx5_0:1 --oversubscribe --use-hwthread-cpus --hostfile 10-clients.txt  --allow-run-as-root"

During the IO500 running, the system was fully dedicated to benchmarking.

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

Dell Lightning File System does not perform any data caching.

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 system is a stand-alone storage system, with clients accessing the storage via POSIX

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 IO500 benchmark was ran 20 times in a loop and the IO500 scores have a Coefficient of Variance of 0.6%

The results were reviewed and they are within the physical capabilities of the storage system and networks                                                                                                                                                               

There is no data caching mechanism and so all data are persistent to storage before acknowledging the close operation