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The largest file size that OneFS currently supports is increased to 16 TB in OneFS 8.2.2 and later, up from a maximum of 4 TB in prior releases.
To support files larger than 4 TB, adequate space is required in all of a cluster’s disk pools in order to avoid a potential performance impact. As such, the following hard requirements apply:
Large file support requirement | Description |
Version | A cluster must be running OneFS 8.2.2 or later to enable large file support. |
Disk Pool | A maximum sized file (16 TB) plus protection can consume no more than 10% of any disk pool. This translates to a minimum disk pool size of 160 TB plus protection. |
SyncIQ Policy | All SyncIQ remote clusters must be running OneFS 8.2.2 or later and satisfy the restrictions for minimum disk pool size and SyncIQ policies. |
After installing OneFS 8.2.2 or later a cluster intended for large file support, the following CLI utility will verify that the cluster’s disk pools and existing SyncIQ policies meet the above requirements:
# isi_large_file -c
Once the validation confirms that the cluster meets the requirements, the following CLI command is then run to enable large file support:
# isi_large_file -e
Upon successfully enabling large file support, the ‘cluster full’ alert threshold is automatically lowered to 85% from the OneFS default of 95%. This is to ensure that adequate space is available for large file creation, repair, and restriping. Also, any SyncIQ replication partners must also be running OneFS 8.2.2 or later, adhere to the above minimum disk pool size, and have the large file feature enabled.
Any disk pool management commands that violate the large file support requirements are not allowed. Once enabled, disk pools are periodically checked for compliance and OneFS will alert if a disk pool fails to meet the minimum size requirement.
Be aware that, once enabled, large file support cannot be disabled on a cluster. This may affect future expansion planning for the cluster and all its SyncIQ replication partners.
For more information about OneFS limits and guidelines, see the PowerScale OneFS Technical Specifications Guide.