From de499eb67cda5c852605fe365950844412cbe789 Mon Sep 17 00:00:00 2001 From: Pavel Dovgalyuk Date: Tue, 17 Sep 2019 14:58:02 +0300 Subject: [PATCH] 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: Pavel Dovgalyuk Signed-off-by: Kevin Wolf --- docs/replay.txt | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/docs/replay.txt b/docs/replay.txt index ee6aee9861..ce97c3f72f 100644 --- a/docs/replay.txt +++ b/docs/replay.txt @@ -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 ' command created the snapshot and 'loadvm ' restores it. To prevent corruption of the original disk image, use overlay files linked to the original images.