[libvirt] [PATCH 2/2] Adjust block size used by dd to speed QEMU domain save operations.

See https://bugzilla.redhat.com/show_bug.cgi?id=599091 Saving a paused 512MB domain took 3m47s with the old block size of 512 bytes. Changing the block size to 1024*1024 decreased the time to 56 seconds. (Doubling again to 2048*1024 yielded 0 improvement; lowering to 512k increased the save time to 1m10s, about 20%) --- src/qemu/qemu_monitor.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h index 1870b22..fd39b1c 100644 --- a/src/qemu/qemu_monitor.h +++ b/src/qemu/qemu_monitor.h @@ -261,7 +261,7 @@ int qemuMonitorMigrateToCommand(qemuMonitorPtr mon, unsigned int background, const char * const *argv); -# define QEMU_MONITOR_MIGRATE_TO_FILE_BS 512llu +# define QEMU_MONITOR_MIGRATE_TO_FILE_BS (1024llu * 2048) int qemuMonitorMigrateToFile(qemuMonitorPtr mon, unsigned int background, -- 1.7.0.1