diff options
| -rw-r--r-- | docs/tools/qemu-storage-daemon.rst | 19 | ||||
| -rw-r--r-- | storage-daemon/qemu-storage-daemon.c | 4 |
2 files changed, 23 insertions, 0 deletions
diff --git a/docs/tools/qemu-storage-daemon.rst b/docs/tools/qemu-storage-daemon.rst index 086493ebb3..3ec4bdd914 100644 --- a/docs/tools/qemu-storage-daemon.rst +++ b/docs/tools/qemu-storage-daemon.rst @@ -74,6 +74,7 @@ Standard options: .. option:: --export [type=]nbd,id=<id>,node-name=<node-name>[,name=<export-name>][,writable=on|off][,bitmap=<name>] --export [type=]vhost-user-blk,id=<id>,node-name=<node-name>,addr.type=unix,addr.path=<socket-path>[,writable=on|off][,logical-block-size=<block-size>][,num-queues=<num-queues>] --export [type=]vhost-user-blk,id=<id>,node-name=<node-name>,addr.type=fd,addr.str=<fd>[,writable=on|off][,logical-block-size=<block-size>][,num-queues=<num-queues>] + --export [type=]fuse,id=<id>,node-name=<node-name>,mountpoint=<file>[,growable=on|off][,writable=on|off] is a block export definition. ``node-name`` is the block node that should be exported. ``writable`` determines whether or not the export allows write @@ -92,6 +93,16 @@ Standard options: ``logical-block-size`` sets the logical block size in bytes (the default is 512). ``num-queues`` sets the number of virtqueues (the default is 1). + The ``fuse`` export type takes a mount point, which must be a regular file, + on which to export the given block node. That file will not be changed, it + will just appear to have the block node's content while the export is active + (very much like mounting a filesystem on a directory does not change what the + directory contains, it only shows a different content while the filesystem is + mounted). Consequently, applications that have opened the given file before + the export became active will continue to see its original content. If + ``growable`` is set, writes after the end of the exported file will grow the + block node to fit. + .. option:: --monitor MONITORDEF is a QMP monitor definition. See the :manpage:`qemu(1)` manual page for @@ -196,6 +207,14 @@ domain socket ``vhost-user-blk.sock``:: --blockdev driver=qcow2,node-name=qcow2,file=file \ --export type=vhost-user-blk,id=export,addr.type=unix,addr.path=vhost-user-blk.sock,node-name=qcow2 +Export a qcow2 image file ``disk.qcow2`` via FUSE on itself, so the disk image +file will then appear as a raw image:: + + $ qemu-storage-daemon \ + --blockdev driver=file,node-name=file,filename=disk.qcow2 \ + --blockdev driver=qcow2,node-name=qcow2,file=file \ + --export type=fuse,id=export,node-name=qcow2,mountpoint=disk.qcow2,writable=on + See also -------- diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c index 72900dc2ec..fc8b150629 100644 --- a/storage-daemon/qemu-storage-daemon.c +++ b/storage-daemon/qemu-storage-daemon.c @@ -98,6 +98,10 @@ static void help(void) " export the specified block node over NBD\n" " (requires --nbd-server)\n" "\n" +" --export [type=]fuse,id=<id>,node-name=<node-name>,mountpoint=<file>\n" +" [,growable=on|off][,writable=on|off]\n" +" export the specified block node over FUSE\n" +"\n" " --monitor [chardev=]name[,mode=control][,pretty[=on|off]]\n" " configure a QMP monitor\n" "\n" |