Vmkfstools: Difference between revisions

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Revision as of 23:15, 27 November 2014

1,362 bytes added , 27 November 2014

→‎Examples

Wila

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 === Examples ===
+==== Export a VM disk ====
 Export a VM disk in 2GB chunks, note that since [[Esxcli#enable_2GB_Sparse_disks|ESXi 5.1+ the 2GB sparse driver is disabled]].
   vmkfstools -i /vmfs/volumes/storagename/YourVM/YourVM.vmdk -d 2gbsparse /vmfs/volumes/storage2/YourVM/YourVM.vmdk
+==== Check or repair a disk ====
   -x, --fix -[check|repair]
 This option will check and/or repair the virtual disk in case of an unclean shutdown.
@@ Line 78: / Line 80: @@
   Disk is error free
+==== Set a UUID ====
   -J, --miscop [setuuid | getuuid]
 'setuuid´ option creates a unique identifier (UUID) for the virtual disk and stores the UUID in the descriptor file of the
@@ Line 86: / Line 89: @@
 ´getuuid´ option displays the UUID of the virtual disk.
+==== dumpfs ====
 dumpfs can be used by specifying either "-D | --dumpfs" and specifying a VMFS volume, file or folder.
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   Addr <4, 0, 0>, gen 1, links 4, type dir, flags 0, uid 0, gid 0, mode 1755
   len 1260, nb 1 tbz 0, cow 0, zla 1, bs 1048576
+==== activehosts ====
 activehosts can be used by specifying "--activehosts" and specifying a VMFS volume
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   Found 1 actively heartbeating hosts on volume '/vmfs/volumes/esx4-1-local-storage-1/'
   (1): MAC address 00:50:56:92:3f:86
+==== punchzero ====
+Since vSphere 5.1 there's an option to shrink disks besides the normally required storage vmotion.
+With the guest shut down you can run vmkfstools with the punchzero option.
+Reclaim disk space by returning unused blocks of data in the virtual disk to the host OS.
+Note that this will only work if your virtual disk is of type thin.
+You will also need to zero out the unused blocks of data in the guest OS.
+For a windows VM, you can use Microsoft's tool [http://technet.microsoft.com/en-us/sysinternals/bb897443.aspx sdelete].
+Run it as
+ sdelete -z c:
+Note that the -z option is needed as of sdelete version 1.6
+For a linux based VM, run a command like:
+ cat /dev/zero > zero.fill;sync;sleep 1;sync;rm -f zero.fill
+to zero out the unused space.
+Note of warning that you should stop database -and other disk intensive- services before running the above.
-Reclaim disk space by returning unused blocks of data in the virtual disk to the host OS. This will only work if your virtual disk is of type thin.
 Example:
-  # vmkfstools --punchzero myvm.vmdk
+  # vmkfstools --punchzero disk.vmdk
   vmfsDisk: 1, rdmDisk: 0, blockSize: 1048576
   Hole Punching: 3% done.
+After you're done and list the VM from within the console, it looks like nothing has changed, in this example the disk is 10GB in size.
+ # ls -lh *.vmdk
+ -rw-------    1 root     root       10.0G Nov 27 20:58 disk-flat.vmdk
+ -rw-------    1 root     root         527 Nov 27 21:02 disk.vmdk
+If you use the command du however then you can see the difference:
+ # du -hs *.vmdk
+.3G    disk-flat.vmdk
+       disk.vmdk
+You can also use the vSphere Client data browser to see the effect of reclaiming disk space
 === Links ===