[Devel] vzmigrate filesystem rsync correction

[Ola Lundqvist]

Hi

During testing and debugging of a problem on Debian systems
(which I later found out was corrected in 3.0.13 version) I found
that the rsync commands in vzmigrate can give quite unexpected
results.

The command looks basically like this:
rsync -aH ${from} ${to}

This means that files are copied from ${from} to ${to}, but if
files already exist on ${to} from some older copy the old files
that do not exist on ${from} will not be deleted.

This is a problem if --keep-dst or --online option is used.

There are two places where the rsync command is used for transfer
of filesystem data.

The first one is right after 'log 1 "Syncing private"'. If --keep-dst
is used this is a problem. The solution is to add the --delete option
to rsync.

The second one is right after 'log 2 "Syncing private (2nd pass)"'
and it is a problem if --online option is used and a file has been
deleted between this run and the first rsync run.
The solution is to add the --delete option to rsync.

The following patch has been applied to the Debian (experimental version)
packaged version of vzctl. Patched against 3.0.13:

--- vzctl-3.0.13.orig/vzmigrate
+++ vzctl-3.0.13/vzmigrate
@@ -391,7 +391,7 @@
 fi
 
 log 1 "Syncing private"
-if ! rsync -aH --progress "$VE_PRIVATE" "root@$host:${VE_PRIVATE%/*}" | \
+if ! rsync -aH --delete --progress "$VE_PRIVATE" "root@$host:${VE_PRIVATE%/*}" | \
                grep "% of" | awk -v ORS="\r" '{print $10}'; then
        log 1 "Failed to sync VE private areas"
        undo_quota_on
@@ -444,7 +444,7 @@
 if [ "$state" = "running" ]; then
        log 2 "Syncing private (2nd pass)"
        time_rsync2=$(date +%s.%N)
-       if ! rsync -aH "$VE_PRIVATE" "root@$host:${VE_PRIVATE%/*}"; then
+       if ! rsync -aH --delete "$VE_PRIVATE" "root@$host:${VE_PRIVATE%/*}"; then
                log 1 "Failed to sync VE private areas"
                undo_source_stage
                exit $MIG_ERR_COPY

Will attach as well if the cut and paste made it non-applieable.

The patch is licensed under GNU/GPL.

Regards,

// Ola

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 --------------------- Ola Lundqvist ---------------------------
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