Fix for fatal error when GPT was used and only MBR was cleaned

obourdon · obourdon · commit 5fcf3f066ccd · 2018-05-17T12:51:55.000+02:00
You can generate this error if after having provisioned a node
using GPT partitioning, you clean its MBR using say
dd if=/dev/zero bs=1024 count=1 of=/dev/sda
and then cleanup all Ironic/Bifrost informations to get it
reprovisioned.
In this case sgdisk -Z returns an error and last_error field
in Ironic contains:
Error writing image to device: Writing image to device
        /dev/sda failed with exit code 2
Caution: invalid main GPT header, but valid backup;
        regenerating main header\nfrom backup!\n
        \nInvalid partition data!\

Change-Id: Ib617737fff5e40cb376edda0232e0726d9c71231
diff --git a/ironic_python_agent/shell/write_image.sh b/ironic_python_agent/shell/write_image.sh
@@ -36,7 +36,7 @@ DEVICE="$2"
 # In production this will be replaced with secure erasing the drives
 # For now we need to ensure there aren't any old (GPT) partitions on the drive
 log "Erasing existing GPT and MBR data structures from ${DEVICE}"
-sgdisk -Z $DEVICE
+sgdisk -Z $DEVICE || sgdisk -o $DEVICE
 
 log "Imaging $IMAGEFILE to $DEVICE"
 
