use backup/resore

pages/ShrinkLinuxDisk.md

@@ -10,21 +10,46 @@ Shutdown the VM
 gnt-instance shutdown rpki.dfw.rg.net
 ```
 
-We need to get the uuid of the volume to be reduced
-
-```
-# gnt-instance info rpki.dfw.rg.net | grep primary
-    - primary: vm3.dfw.rg.net
-          on primary: /dev/ganeti/a5ce213c-d455-4cee-a173-4c3c72d81e68.disk0_data (253:10)
-          on primary: /dev/ganeti/a5ce213c-d455-4cee-a173-4c3c72d81e68.disk0_meta (253:12)
-```
-
-Oops!  See that disk0_meta?  This means there is a drbd secondary. We never figured out how to deal with that, so you have to convert the instance to plain before proceeding.
+Make sure the VM is not DRBD mirrored.  If it is, then
 
 ```
 gnt-instance modify -t plain --no-wait-for-sync rpki.dfw.rg.net
 ```
 
+
+## Shrink the partition(s)
+
+Use a gparted bootable iso or a Linux live bootable iso to run
+`gparted` to shrink the partitions.
+
+
+## Backup the instance
+
+Make sure the destination node has sufficient space.  If not, on the
+destination node, you can
+
+```
+lvextend -L +128G /dev/mapper/ganeti-var
+resize2fs /dev/mapper/ganeti-var
+```
+
+Then
+
+```
+gnt-backup export -n vm3 rpki.dfw.rg.net
+```
+
+## Restore into Smaller Space
+
+```
+gnt-backup import -n vm0 --src-node=vm3 --disk 0:size=21G -t plain rpki.dfw.rg.net
+```
+
+## And you should be good to go
+
+
+# SKIP THE REST OF THIS!!!  The above is the hack you want
+
 ## Tell Ganeti to Chill
 
 First we need to stop ganeti and backup the config file on the master
@@ -80,4 +105,8 @@ gnt-instance modify -t drbd --no-wait-for-sync -n vm2 rpki.dfw.rg.net
 gnt-instance start rpki.dfw.rg.net
 ```
 
-And Bob's your uncle.
+And Bob's your uncle.
+
+---
+
+2020.10.03