doc/bluestore: add SPDK usage for bluestore

Signed-off-by: Haomai Wang <haomai@xsky.com>

diff --git a/doc/rados/configuration/bluestore-config-ref.rst b/doc/rados/configuration/bluestore-config-ref.rst
index ee983464318542186acc999d990048be8220febf..7af895779b53cd8c338c3be312badcb63082f846 100644 (file)
--- a/doc/rados/configuration/bluestore-config-ref.rst
+++ b/doc/rados/configuration/bluestore-config-ref.rst
@@ -294,3 +294,33 @@ set with::
 :Type: Unsigned Integer
 :Required: No
 :Default: 64K
+
+SPDK Usage
+==================
+
+If you want to use SPDK driver for NVME SSD, you need to specify NVMe serial
+number here with "spdk:" prefix for ``bluestore_block_path``.
+
+For example, users can find the serial number with::
+
+  $ lspci -vvv -d 8086:0953 | grep "Device Serial Number"
+
+and then set::
+
+  bluestore block path = spdk:...
+
+If you want to run multiple SPDK instances per node, you must specify the
+amount of dpdk memory size in MB each instance will use, to make sure each
+instance uses its own dpdk memory
+
+In most cases, we only need one device to serve as data, db, db wal purposes.
+We need to make sure configurations below to make sure all IOs issued under
+SPDK.::
+
+  bluestore_block_db_path = ""
+  bluestore_block_db_size = 0
+  bluestore_block_wal_path = ""
+  bluestore_block_wal_size = 0
+
+Otherwise, the current implementation will setup symbol file to kernel
+filesystem location and uses kernel driver to issue DB/WAL IO.