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authorSage Weil <sage@newdream.net>2011-09-15 14:11:10 -0700
committerKevin Wolf <kwolf@redhat.com>2011-09-20 12:27:44 +0200
commit9e1fbcde578b0ab3cd2732e5334e772ab19371ac (patch)
tree0f58bf2ec78b09e296e575b5c9a47dee3f38834c /block/rbd.c
parentf9fe18ec772d2852caaa7ca3cb72720d6822edca (diff)
rbd: update comment heading
Properly document the configuration string syntax and semantics. Remove (out of date) details about the librbd implementation. Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/rbd.c')
-rw-r--r--block/rbd.c28
1 files changed, 13 insertions, 15 deletions
diff --git a/block/rbd.c b/block/rbd.c
index f64b2e0542..23d8751d03 100644
--- a/block/rbd.c
+++ b/block/rbd.c
@@ -13,35 +13,33 @@
#include "qemu-common.h"
#include "qemu-error.h"
-
#include "block_int.h"
#include <rbd/librbd.h>
-
-
/*
* When specifying the image filename use:
*
* rbd:poolname/devicename[@snapshotname][:option1=value1[:option2=value2...]]
*
- * poolname must be the name of an existing rados pool
+ * poolname must be the name of an existing rados pool.
*
- * devicename is the basename for all objects used to
- * emulate the raw device.
+ * devicename is the name of the rbd image.
*
- * Each option given is used to configure rados, and may be
- * any Ceph option, or "conf". The "conf" option specifies
- * a Ceph configuration file to read.
+ * Each option given is used to configure rados, and may be any valid
+ * Ceph option, "id", or "conf".
*
- * Metadata information (image size, ...) is stored in an
- * object with the name "devicename.rbd".
+ * The "id" option indicates what user we should authenticate as to
+ * the Ceph cluster. If it is excluded we will use the Ceph default
+ * (normally 'admin').
*
- * The raw device is split into 4MB sized objects by default.
- * The sequencenumber is encoded in a 12 byte long hex-string,
- * and is attached to the devicename, separated by a dot.
- * e.g. "devicename.1234567890ab"
+ * The "conf" option specifies a Ceph configuration file to read. If
+ * it is not specified, we will read from the default Ceph locations
+ * (e.g., /etc/ceph/ceph.conf). To avoid reading _any_ configuration
+ * file, specify conf=/dev/null.
*
+ * Configuration values containing :, @, or = can be escaped with a
+ * leading "\".
*/
#define OBJ_MAX_SIZE (1UL << OBJ_DEFAULT_OBJ_ORDER)