diff options
| author | Peter Krempa <pkrempa@redhat.com> | 2014-07-07 14:38:10 +0200 |
|---|---|---|
| committer | Peter Krempa <pkrempa@redhat.com> | 2014-07-14 09:26:39 +0200 |
| commit | 6f04fb151bae22ce349190e5c769334403b025ce (patch) | |
| tree | fe2923121743fc28d0d99ed9d36157c437f88a40 /tools | |
| parent | 500f80a595216d38bbd7e462f99e2a7febc988de (diff) | |
| download | libvirt-6f04fb151bae22ce349190e5c769334403b025ce.tar.gz | |
doc: Be more specific about semantics of _REUSE_EXT flag
Snapshots and block-copy have a flag that forces qemu to re-use existing
file. Our docs weren't exactly clear on what the existing file should
contain for this to actually work.
Re-word the docs a bit to state that the file needs to be pre-created in
the desired format and the backing chain metadata needs to be set prior
to handing it over to qemu.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1084360
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/virsh.pod | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/tools/virsh.pod b/tools/virsh.pod index 5da71c3f34..1a2b01fb2c 100644 --- a/tools/virsh.pod +++ b/tools/virsh.pod @@ -876,10 +876,11 @@ flattens the entire chain; but if I<--shallow> is specified, the copy shares the backing chain. If I<--reuse-external> is specified, then I<dest> must exist and have -contents identical to the resulting backing file (that is, it must -start with contents matching the backing file I<disk> if I<--shallow> -is used, otherwise it must start empty); this option is typically used -to set up a relative backing file name in the destination. +sufficient space to hold the copy. If I<--shallow> is used in +conjunction with I<--reuse-external> then the pre-created image must have +guest visible contents identical to guest visible contents of the backing +file of the original image. This may be used to modify the backing file +names on the destination. The format of the destination is determined by the first match in the following list: if I<--raw> is specified, it will be raw; if @@ -3172,7 +3173,8 @@ metadata again). If I<--reuse-external> is specified, and the snapshot XML requests an external snapshot with a destination of an existing file, then the -destination must exist, and is reused; otherwise, a snapshot is refused +destination must exist and be pre-created with correct format and +metadata. The file is then reused; otherwise, a snapshot is refused to avoid losing contents of the existing files. If I<--quiesce> is specified, libvirt will try to use guest agent @@ -3233,8 +3235,9 @@ results in the following XML: If I<--reuse-external> is specified, and the domain XML or I<diskspec> option requests an external snapshot with a destination of an existing -file, then the destination must exist, and is reused; otherwise, a -snapshot is refused to avoid losing contents of the existing files. +file, then the destination must exist and be pre-created with correct +format and metadata. The file is then reused; otherwise, a snapshot +is refused to avoid losing contents of the existing files. If I<--quiesce> is specified, libvirt will try to use guest agent to freeze and unfreeze domain's mounted file systems. However, |