Use expect_empty_remote_list flag when checking if remote list should be empty or not

[zfs-ubuntu/.git] / zfs-replicate

diff --git a/zfs-replicate b/zfs-replicate
index 9dfd9f8cbef7997e28bb6bd9ce72d164ce812250..60a23457d583c8555a0df88384cd44e29d0277cf 100755 (executable)
--- a/zfs-replicate
+++ b/zfs-replicate
@@ -18,6 +18,9 @@ remote=$1
 remote_fs=$2
 remote_pool=${2%%/*}
 
+# return non-zero exit code if any command in the pipe fails
+set -o pipefail
+
 # get the backup pool from the command line or the config file if not specified
 if [[ -n $3 ]]; then
     backup_pool=$3
@@ -155,8 +158,10 @@ $ssh $remote \
     $zfs list -H -t snapshot |
     grep ^${remote_fs}@ |
     awk '{print$1}' > $remote_list
-if [ $? != 0 ]; then
-  fatal_and_exit "-E- remote $zfs list on $hostname command failed" $mailto
+if [[ $? != 0 ]] && [[ $expect_empty_remote_list == 0 ]]; then
+  echo "-W- Unable to find $remote_fs on the remote host $hostname. Unable to proceed since the"
+  echo "    expect_empty_remote_list option has not been set to allow this, skipping replicate operation."
+  fatal_and_exit "-E- remote $zfs list on $hostname for $remote_fs command failed" $mailto
 fi
 
 # List the snapshots on the local machine.
@@ -167,9 +172,9 @@ $zfs list -H -t snapshot |
     grep ^${backup_pool}/${remote_fs}@ |
     grep -v ^${backup_pool}/${current_backup_marker} | 
     awk "{gsub(/^$backup_pool./,\"\",\$1); print\$1}" > $local_list
-if [ $? != 0 ]; then
-  fatal_and_exit "-E- local $zfs list on $hostname command failed" $mailto
-fi
+# If no local snapshots exist, we may need to send the entire filesystem, which we'll do later
+# So, no error check here as a non-zero return code means the local filesystem or snaps are missing
+# We'll catch this later on as a case where we need to send the entire filesystem
 
 # Destroy the current backup marker snapshot on the remote system if it exists
 grep -q ${current_backup_marker} $remote_list
@@ -203,9 +208,13 @@ if [ $no_markers == 0 ]; then
   # backup was interrupted for some reason. If we don't do this, the zfs send -R command
   # below may complain about snaps already existing as it tries to resend from the 
   # previous backup marker again from a previously interrupted replicate.
-  $zfs rollback -r ${backup_pool}/${previous_backup_marker} 
+  $zfs rollback -rf ${backup_pool}/${previous_backup_marker} 
   if [ $? != 0 ]; then
-    fatal_and_exit "-E- remote incremental $zfs rollback command failed on $hostname" $mailto
+    sleep 120
+    $zfs rollback -rf ${backup_pool}/${previous_backup_marker}
+    if [ $? != 0 ]; then
+      fatal_and_exit "-E- remote incremental $zfs rollback command failed on $hostname" $mailto
+    fi
   fi
   # Now it should be safe to send the snaps
   replicate "$zfs send -Rc -I${previous_backup_marker} ${current_backup_marker}"
@@ -260,6 +269,7 @@ fi
 # don't check the return codes here because these may not exist, and that is ok
 $zfs destroy ${backup_pool}/${previous_backup_marker} > /dev/null 2>&1
 $ssh $remote $zfs destroy ${previous_backup_marker} > /dev/null 2>&1
+sleep 1
 
 # Rename the current backup marker to be the previous backup marker
 $zfs rename ${backup_pool}/${current_backup_marker} ${backup_pool}/${previous_backup_marker}