diff --git a/upsnapz.sh b/upsnapz.sh
index 91d5622..c2bff9c 100755
--- a/upsnapz.sh
+++ b/upsnapz.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# Time-stamp: <2025-02-10 07:05:07 nomad>
+# Time-stamp: <2025-02-10 07:14:16 nomad>
 
 # Michel Le Cocq <lecocq@ipgp.fr>
 #                <nomad@neuronfarm.net>
@@ -30,6 +30,47 @@
 #
 # regarder si un nouveau kernel existe et si oui faire ce qu'il y a a faire
 
+function cleansnap
+{
+   printf '\nClean snapshot.\n'
+   
+   printf 'Current available bootfs:\n'
+   zfs list -o name,used,usedbysnapshots -r zroot/ROOT -s creation | grep -v '^zroot/ROOT .*'
+   oldest=$(zfs list -H -o name -r zroot/ROOT -s creation | grep -v '^zroot/ROOT$' | head -n 1)
+   oldestdate=$(echo $oldest | cut -d "_" -f 3- | tr '_' '-')
+   current=$(zpool get -H bootfs zroot -o value)
+   printf '\ncurrent bootfs: %s\n' $current
+   printf 'oldest  bootfs: %s\n' $oldest
+   printf '\nzroot/ROOT status : \n'
+   zfs list -o used,available,quota,usedbychildren zroot/ROOT
+   
+   printf '\nsnapshot to clean older than %s:\n' $oldestdate
+   zfs list -H -o name -t snapshot -s creation -r $current | grep $oldestdate -B10000 | grep -v $oldestdate
+   
+   if [ $? -ne 1 ]
+   then
+       printf '\nDo snapshots cleanup ? : %s [Y-n]' $sugsname    
+       read docleanup
+       if [ -z $dopromote ]
+       then
+   	dopromote='y'
+       fi
+       
+       if [[ "$dopromote" == "y" ]]
+       then
+   	for z in $(zfs list -H -o name -t snapshot -s creation -r $current | grep $oldestdate -B10000 | grep -v $oldestdate)
+   	do
+   	   printf 'zfs destroy %s\n' $z
+   	   sudo zfs destroy $z
+   	done
+       fi
+       usedbysnapshots=$(zfs list -H -o usedbysnapshots $current)
+       printf '\nused by snapshot : %s\n' $usedbysnapshots
+   else
+       printf '\tno snapshot older than %s\n' $oldestdate
+   fi
+}
+
 function check_zpool_status
 {
     # check zpool status if it's upgradable
@@ -293,6 +334,6 @@ check_zpool_status
 check_ZFS_BOOT_MENU
 echo
 zpool status
+cleansnap
 printf '\nNothing else to do.\n'
 
-#~/bin/clean-snapshot.sh