[CLOUDSTACK-10128] Template from snapshot not merging vhd files

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 4.10.0.0, 4.9.2.0, 4.5.2.2, 4.9.3.0
• Fix Version/s: 4.11.0.0
• Component/s: Management Server
• Security Level: Public (Anyone can view this level - this is the default.)
• Environment: Production environment running ACS 4.5.2.2, 4.9.2.0, 4.9.3.0 ; XenServer 6.5 ; Primary Storage NFS and ISCSI ; Fresh install running 4.5.2.2, 4.9.2.0, 4.9.3.0 and 4.10
• Assignee: Rafael Weingärtner
• Reporter: Marcelo Lima
• Created: 01/Nov/17 18:27
• Updated: 19/Feb/18 20:54
• Resolved: 08/Jan/18 09:56

Description

If we have two or more snapshots of a ROOT disk and try to create a template from differencial snapshots, CloudStack not merging the vhd files on secondary storage.

Steps to reproduce

1. Create virtual machine - OK

2. Create a manual snapshot from ROOT volume - OK
The vhd of first snapshot (snapshot-base) is stored on secondary storage correctly

[root@acs01 6]# ls -l /exports/secondary/snapshots/2/6/011a7650-a13f-4332-8c72-2428a002affc.vhd
rw-rr- 1 root root 1767191040 Nov 1 12:12 /exports/secondary/snapshots/2/6/011a7650-a13f-4332-8c72-2428a002affc.vhd

[root@acs01 6]# md5sum /exports/secondary/snapshots/2/6/011a7650-a13f-4332-8c72-2428a002affc.vhd
240e5e424552d44b5d297895b064beee /exports/secondary/snapshots/2/6/011a7650-a13f-4332-8c72-2428a002affc.vhd

3. Create a template from snapshot-base - OK

[root@acs01 6]# ls -l /exports/secondary/template/tmpl/2/206/be3311d9-8e59-4240-968d-73d7a6eecfdd.vhd
rw-rr- 1 root root 1767191040 Nov 1 12:17 /exports/secondary/template/tmpl/2/206/be3311d9-8e59-4240-968d-73d7a6eecfdd.vhd

[root@acs01 6]# md5sum /exports/secondary/template/tmpl/2/206/be3311d9-8e59-4240-968d-73d7a6eecfdd.vhd
240e5e424552d44b5d297895b064beee /exports/secondary/template/tmpl/2/206/be3311d9-8e59-4240-968d-73d7a6eecfdd.vhd

This template from snapshot-base boot normally

4. Create new file (1GB) on ROOT volume

5. Create new snapshot (snapshot-diff) from ROOT volume - OK

[root@acs01 6]# ls -l /exports/secondary/snapshots/2/6/
total 2840056
rw-rr- 1 root root 1767191040 Nov 1 12:12 011a7650-a13f-4332-8c72-2428a002affc.vhd <- snapshot-base
rw-rr- 1 root root 1141019136 Nov 1 12:21 1503adaa-4f6e-4f9c-8d80-68663baa86b8.vhd <- snapshot-diff

6. Create a template from second snapshot - NOK

[root@acs01 6]# ls -lh /exports/secondary/template/tmpl/2/207/4c5c51a1-fcb4-4cc8-8f97-1664a63af262.vhd
rw-rr- 1 root root 1141019136 Nov 1 12:30 /exports/secondary/template/tmpl/2/207/4c5c51a1-fcb4-4cc8-8f97-1664a63af262.vhd

CloudStack not merging snapshot-base and snapshot-diff. Template from second snapshot is corrupted because is based just on differential vhd.

Volume from snapshot work very well

1. Create a volume from snapshot-diff - OK
CloudStack merge two snapshots in one file

[root@acs01 primary]# ls -l /exports/primary/70f1db23-cc59-4ec7-b8d4-ed036228593b.vhd
rw-rr- 1 root root 2843030016 Nov 1 12:34 /exports/primary/70f1db23-cc59-4ec7-b8d4-ed036228593b.vhd

2. Download the new volume to check vhd on secondary storage

[root@acs01 9]# ls -l /exports/secondary/volumes/2/9/ec6e0f65-bb71-4c91-bac3-287cde2106b7.vhd
rw-rr- 1 root root 2843030016 Nov 1 12:35 /exports/secondary/volumes/2/9/ec6e0f65-bb71-4c91-bac3-287cde2106b7.vhd

We test on 4.5.2.2, 4.9.2.0, 4.9.3.0 and 4.10. XenServer 6.5 with SP1 and XenServer 6.5 with all patches.

A workaround is create a volume (data-disk) from latest snapshot, create new snapshot from data-disk and convert to template.

Issue Links

• links to: GitHub Pull Request #2402