Raid module:
============
- SPDK raid bdev module is a new bdev module which is
responsible for striping various NVMe devices and expose the raid bdev
to bdev layer which would enhance the performance and capacity.
- It can support theoretically 256 base devices (currently it is being
tested max upto 8 base devices)
- Multiple strip sizes like 32KB, 64KB, 128KB, 256KB, 512KB etc is
supported. Most of the current testing is focused on 64KB strip size.
- New RPC commands like "create raid bdev", "destroy raid bdev" and "get raid bdevs"
are introduced to configure raid bdev dynamically in a running
SPDK system.
- Currently raid bdev configuration parameters are persisted in the
current SPDK configuration file for across reboot support. DDF will be
introduced later.
High level testing done:
=======================
- Raid bdev is created with 8 base NVMe devices via configuration
file and is exposed to initiator via existing methods. Initiator is
able to see a single NVMe namespace with capacity equal to sum of the
minimum capacities of 8 devices. Initiator was able to run raw
read/write workload, file system workload etc (tested with XFS file
system workload).
- Multiple raid bdevs are also created and exposed to initiator and
tested with file system and other workloads for read/write IO.
- LVS / LVOL are created over raid bdev and exposed to initiator.
Testing was done for raw read/write workloads and XFS file system
workloads.
- RPC testing is done where on the running SPDK system raid bdevs
are created out of NVMe base devices. These raid bdevs (and LVOLs
over raid bdevs) are then exposed to initiator and IO workload was
tested for raw read/write and XFS file system workload.
- RPC testing is done for delete raid bdevs where all raid bdevs
are deleted in running SPDK system.
- RPC testing is done for get raid bdevs where existing list of
raid bdev names is printed (it can be all raid bdevs or only
online or only configuring or only offline).
- RPC testing is done where raid bdevs and underlying NVMe devices
relationship was returned in JSON RPC commands
Change-Id: I10ae1266f8f2cca3c106e4df8c1c0993ddf435d8
Signed-off-by: Kunal Sablok <kunal.sablok@intel.com>
Reviewed-on: https://review.gerrithub.io/410484
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
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