VMware
Virtual Disk Development Kit:

This Question is Not Answered

1 "correct" answer available (10 pts) 2 "helpful" answers available (6 pts)
5 Replies Last post: Nov 9, 2009 5:29 AM by tos2k  

VixDiskLib Opening delta disks (snapshots posted: Oct 28, 2009 5:26 AM

Click to view tos2k's profile Expert
tos2k
307 posts since
May 11, 2007
Hi!

Is it possible to open delta disks with VixDiskLib? Currently connect fails for me:

Trying to connect to: [TP_SANVOL01] test-Delta/test-Delta.vmx?dcPath=ha-datacenter&dsName=TP_SANVOL01 disk: [TP_SANVOL01]test-Delta/test-Delta-000001.vmdk
conn 0 : connPtr 9522368
** INFO: TicketResolveHostName: Resolving IP address for hostname 192.168.73.204.

** INFO: TicketResolveHostName: Resolved to 192.168.73.204.

** INFO: VixDiskLibVim: TicketLogin

** INFO: VixDiskLibVim: TicketFindDatacenter: dcPath = -ha-datacenter- 

** INFO: VixDiskLibVim: TicketFindVMByDatastorePath: vmxPath = -[TP_SANVOL01] test-Delta/test-Delta.vmx- 

** INFO: VixDiskLibVim: TicketLoadVM

** INFO: VixDiskLibVim: Root Snapshot list has 1 elements.

** INFO: VixDiskLibVim: Unable to find key for disk [TP_SANVOL01]test-Delta/test-Delta-000001.vmdk, trying snapshot tree.

** INFO: VixDiskLibVim: TicketCollectSnapshots

** INFO: VixDiskLibVim: TicketLoadSnapshot

** INFO: VixDiskLibVim: TicketLoadVMCb

** INFO: VixDiskLibVim: TicketLoadInternalSic 

** INFO: VixDiskLibVim: TicketLoadNfcTicket: Request FileManagement diskKey = 2000, readOnly = 0, openSnapshot = 1 

** INFO: VixDiskLibVim: TicketLogout 

---EX caught: 0  :  System.OverflowException: Arithmetic operation resulted in an overflow.
   at vddkNativeTest.Module1.Init(String hostIp, String user, String pass, String vmxSource, String vmxTarget, String sourceDatastore, String targetDatastore, String currentDisk, String targetDisk, String datacenter)


The VM has that snapshot, is powered-off and the connect works fine for base disks... Any ideas?

Tos2k

Re: VixDiskLib Opening delta disks (snapshots

1. Oct 28, 2009 9:37 AM in response to: tos2k
Click to view RColbert's profile Enthusiast
RColbert
98 posts since
Mar 11, 2005

Are you using the .NET wrapper? If so, you should change your VixError (in _native.vb) to be uint64. In the original posted wrapper, I think it was set to Integer which isn't big enough.

Re: VixDiskLib Opening delta disks (snapshots

2. Oct 28, 2009 1:07 PM in response to: RColbert
Click to view tos2k's profile Expert
tos2k
307 posts since
May 11, 2007
Have you tried to read delta files?

The VB wrapper works like it charm for base vmdks...

Tos2k

Re: VixDiskLib Opening delta disks (snapshots

3. Oct 28, 2009 1:36 PM in response to: tos2k
Click to view RColbert's profile Enthusiast
RColbert
98 posts since
Mar 11, 2005

I have created,opened and deleted snapshot files w/ the VDDK.

What I discovered though is when you get an arithmetic overflow exception, it is usually because a function tried to come back w/ a VixError that was larger than the datatype defined for it.

If you fix the VixError enum, you should be able to get a real error code back from the VDDK which may help identify why you can't open the detlas.

Re: VixDiskLib Opening delta disks (snapshots

4. Oct 29, 2009 5:18 AM in response to: RColbert
Click to view tos2k's profile Expert
tos2k
307 posts since
May 11, 2007
Hi!
So ou did not try to write to a delta file? Would be kind of you if you would try that, as I do not get that to work.
Changing the connect call from
err = VixDiskLib_Open(connPtr0, targetDisk, VIXDISKLIB_FLAG_OPEN_SINGLE_LINK, diskPtr0)
to
err = VixDiskLib_Open(connPtr0, targetDisk, VIXDISKLIB_FLAG_OPEN_READ_ONLY, diskPtr0)

avoids the error, but of course in unsuitable for writing to the file:


** INFO: TicketResolveHostName: Resolving IP address for hostname 192.168.73.204.

** INFO: TicketResolveHostName: Resolved to 192.168.73.204.

** INFO: VixDiskLibVim: TicketLogin

** INFO: VixDiskLibVim: TicketFindDatacenter: dcPath = -ha-datacenter- 

** INFO: VixDiskLibVim: TicketFindVMByDatastorePath: vmxPath = -[TP_SANVOL01] test-Delta_1/test-Delta.vmx- 

** INFO: VixDiskLibVim: TicketLoadVM

** INFO: VixDiskLibVim: Root Snapshot list has 1 elements.

** INFO: VixDiskLibVim: Unable to find key for disk [TP_SANVOL01]test-Delta_1/test-Delta.vmdk, trying snapshot tree.

** INFO: VixDiskLibVim: TicketCollectSnapshots

** INFO: VixDiskLibVim: TicketLoadSnapshot

** INFO: VixDiskLibVim: TicketLoadVMCb

** INFO: VixDiskLibVim: TicketLoadInternalSic 

** INFO: VixDiskLibVim: TicketLoadNfcTicket: Request GetVMFiles diskKey = 2000, readOnly = 1, openSnapshot = 1 

** INFO: VixDiskLibVim: TicketLogout 

open 0 : diskPtr 86668552

INFO: Reading/Writing changed data (disk 2000), count of extents: 176 (0, 8589934592 MB capacity) start: 0 length: 8589934592 (8192 MB)


I am assuming that opening delta files for write is not supported, as probably looks like over here too: http://communities.vmware.com/thread/153381
Coudl you try to open a delta file with
VIXDISKLIB_FLAG_OPEN_SINGLE_LINK
instead of VIXDISKLIB_FLAG_OPEN_READ_ONLY and post what you get?

Thx, Tos2k

Re: VixDiskLib Opening delta disks (snapshots

5. Nov 9, 2009 5:29 AM in response to: RColbert
Click to view tos2k's profile Expert
tos2k
307 posts since
May 11, 2007
Hi!
I think there is nothing to fix according to the error codes.
Everything worx like expected:

  • opening files for READ only (no limitation concerning vmdk files!)
  • opening (parent/base) vmdk files for WRITE (SINGLE_LINK)

The only thing that is crashing is opening delta files with SINGLE_LINK.
I am assuming that this is due the format of delta files: Is there any documentation about that? Or is write access limited due undocumented format of delta files?

Tos2k

Actions

Developer SDKs & APIs

Developer Resources

Developer Social Media

Communities