Commit de499eb6 authored by Pavel Dovgalyuk's avatar Pavel Dovgalyuk Committed by Kevin Wolf
Browse files

replay: update docs for record/replay with block devices 



This patch updates the description of the command lines for using
record/replay with attached block devices.

Signed-off-by: default avatarPavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 25863975

docs/replay.txt

+9 −3
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ Usage of the record/replay: 
 * First, record the execution with the following command line:

    qemu-system-i386 \

     -icount shift=7,rr=record,rrfile=replay.bin \

     -drive file=disk.qcow2,if=none,id=img-direct \

     -drive file=disk.qcow2,if=none,snapshot,id=img-direct \

     -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay \

     -device ide-hd,drive=img-blkreplay \

     -netdev user,id=net1 -device rtl8139,netdev=net1 \
@@ -35,7 +35,7 @@ Usage of the record/replay: 
 * After recording, you can replay it by using another command line:

    qemu-system-i386 \

     -icount shift=7,rr=replay,rrfile=replay.bin \

     -drive file=disk.qcow2,if=none,id=img-direct \

     -drive file=disk.qcow2,if=none,snapshot,id=img-direct \

     -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay \

     -device ide-hd,drive=img-blkreplay \

     -netdev user,id=net1 -device rtl8139,netdev=net1 \
@@ -223,7 +223,7 @@ Block devices record/replay module intercepts calls of 
bdrv coroutine functions at the top of block drivers stack.

To record and replay block operations the drive must be configured

as following:

 -drive file=disk.qcow2,if=none,id=img-direct

 -drive file=disk.qcow2,if=none,snapshot,id=img-direct

 -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay

 -device ide-hd,drive=img-blkreplay
@@ -252,6 +252,12 @@ This snapshot is created at start of recording and restored at start 
of replaying. It also can be loaded while replaying to roll back

the execution.



'snapshot' flag of the disk image must be removed to save the snapshots

in the overlay (or original image) instead of using the temporary overlay.

 -drive file=disk.ovl,if=none,id=img-direct

 -drive driver=blkreplay,if=none,image=img-direct,id=img-blkreplay

 -device ide-hd,drive=img-blkreplay



Use QEMU monitor to create additional snapshots. 'savevm <name>' command

created the snapshot and 'loadvm <name>' restores it. To prevent corruption

of the original disk image, use overlay files linked to the original images.