12.3. Tiering Limitations

The following limitations apply to the use Tiering feature:
  • Tiering works only with cache friendly workloads. Attaching a tier volume to a cache unfriendly workload will lead to slow performance. In a cache friendly workload, most of the reads and writes are accessing a subset of the total amount of data. And, this subset fits on the hot tier. This subset should change only infrequently.
  • Tiering feature is supported only on Red Hat Enterprise Linux 7 based Red Hat Gluster Storage. Tiering feature is not supported on Red Hat Enterprise Linux 6 based Red Hat Gluster Storage.
  • In this release, only Fuse and NFSv3 access is supported. Server Message Block (SMB) and NFSv4 access to tiered volume is not supported.
  • Snapshot clones are not supported with the tiered volumes.
  • When you run tier detach commit force, ongoing I/O operation may fail with Transport endpoint is not connected error.
  • Files with hardlinks and softlinks are not migrated.
  • Files on which POSIX locks has been taken are not migrated until all locks are released.
  • Add brick, remove brick, and rebalance operations are not supported on the tiered volume. For information on expanding a tiered volume, see Section 10.3.1, “Expanding a Tiered Volume” and for information on shrinking a tiered volume, see Section 10.4.2, “Shrinking a Tiered Volume ”