Lustre + xiRAID Classic
MEGWARE · MEGWARE xiRAID-test · 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 is a MEGWARE test system setup that was only created for performance tests. It should show the performance of Lustre in conjunction with Xinnor xiRAID Classic software RAID. For these purposes it was built and benchmarked in the specified configuration.
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 is a test system that was only created for performance tests. It was in operation for ~1 week.
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 operating system (AlmaLinux 9.4) is available as open-source
- The file system (Lustre 2.15.65_29_gb07b31d) is also available as open-source
- For this specific test a development release of Lustre was used from: https://build.whamcloud.com/job/lustre-master/
- Xinnor xiRAID Classic (4.1.0) is proprietary RAID software for which a license must be purchased
Anyone can download/purchase the software.
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.
C/P-States were disabled in BIOS. The system didn't use any special OS tunings.
xiRAID and Lustre were installed and configured on servers.
xiRAID6 on OSTs used 64k stripe size. No additional xiRAID tunings were applied.
Ldiskfs on OSTs was created with: -E stride=16,stripe_width=128
Afterwards, the following Lustre tunings were applied:
lctl set_param -P obdfilter.*.brw_size=16
lctl set_param -P obdfilter.*.precreate_batch=1024
lctl set_param -P obdfilter.*.osc.max_pages_per_rpc=4096
lctl set_param -P osc.*.max_pages_per_rpc=4096
lctl set_param -P mdc.*.max_rpcs_in_flight=128
lctl set_param -P osc.*.max_rpcs_in_flight=128
lctl set_param -P mdc.*.max_mod_rpcs_in_flight=127
lctl set_param -P llite.*.checksum_pages=0
lctl set_param -P llite.*.checksums=0
lctl set_param -P osc.*.checksums=0
lctl set_param -P mdc.*.checksums=0
echo "options mdt max_mod_rpcs_per_client=128" > /etc/modprobe.d/lustre.conf
lctl set_param ldlm.namespaces.*.lru_size=6400
lctl set_param mdc.*.max_rpcs_in_flight=128
lctl set_param mdc.*.max_mod_rpcs_in_flight=127
lctl set_param osc.*.max_rpcs_in_flight=128
lctl set_param llite.*.max_read_ahead_mb=2048
Lnet credits were slightly increased:
peer_credits: 16
credits: 512
peercredits_hiw: 8
For Lustre striping etc. see io500.sh.
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 system has power level redundancy (redundant PSUs & USV PDUs).
Each system has 2 InfiniBand HCAs for performance and redundancy.
For storage redundancy Xinnor xiRAID Classic was used (RAID1 for MDT, RAID6 for OST).
The test system did not tolerate a node failure. Node level redundancy for such a setup can be achived with SBB systems with dual-ported drives or EBOF connected to the cluster 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?
The benchmark was executed via HPCX v2.20 OpenMPI on 10 client nodes without any workload manager. Between each run all files were deleted. No special setup process was executed. The system was entirely dedicated to running the benchmark.
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
Besides native Lustre client cache no additional cache was used.
Lustre server side caching was disabled:
lctl set_param osd-ldiskfs.*.read_cache_enable=0
lctl set_param osd-ldiskfs.*.writethrough_cache_enable=0
Xinnor xiRAID Classic does not cache.
Test data size was way above available server and client memory.
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 system is a test system without any specific purpose besides benchmarking.
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 benchmark was run multiple times (>10) with similar results.
The results are below the physical capabilites of the deployed hardware.
Direct I/O and no additonal caching was used to make sure data is written to persistent storage. Furthermore, test data size was way above available server and client memory.