Errors with dd on some esxi hosts...

[jspiel]

I have 3 ESXi 6.0 hosts, all 3 with taste patches installed.

On 2 of them, the dd command is not working if i use the bs= argument.

On the 3rd one, it works as expected.

[code]root@XServe3-ESXi: ls "/vmfs/volumes/XServe3-500SSD-1/ZeusSrv/ZeusSrv-flat.vmdk"

/vmfs/volumes/XServe3-500SSD-1/ZeusSrv/ZeusSrv-flat.vmdk

root@XServe3-ESXi: dd if="/vmfs/volumes/XServe3-500SSD-1/ZeusSrv/ZeusSrv-flat.vmdk" conv=notrunc bs=50  count=1 seek=0

dd: /vmfs/volumes/XServe3-500SSD-1/ZeusSrv/ZeusSrv-flat.vmdk: Invalid argument

[/code]

[code]root@xserve2-esxi: ls "/vmfs/volumes/XServe2-500SSD-1/XServe2-EC/XServe2-EC-flat.vmdk"

/vmfs/volumes/XServe2-500SSD-1/XServe2-EC/XServe2-EC-flat.vmdk

root@xserve2-esxi: dd if="/vmfs/volumes/XServe2-500SSD-1/XServe2-EC/XServe2-EC-flat.vmdk" conv=notrunc bs=50 seek=0

dd: /vmfs/volumes/XServe2-500SSD-1/XServe2-EC/XServe2-EC-flat.vmdk: Invalid argument

[/code]

[code]root@xserve1-esxi: ls "/vmfs/volumes/XServe1-500SSD-2/XServe3VMs/ZeusSrv/ZeusSrv-flat.vmdk"

/vmfs/volumes/XServe1-500SSD-2/XServe3VMs/ZeusSrv/ZeusSrv-flat.vmdk

root@xserve1-esxi: dd if="/vmfs/volumes/XServe1-500SSD-2/XServe3VMs/ZeusSrv/ZeusSrv-flat.vmdk" conv=notrunc bs=50 count=1 seek=0

1+0 records in

1+0 records out

[/code]

I can't understand why such difference ?

[continuum]

I see no errors in your commands.
All 3 of them should work if the VMDKs are not in use.
If a vmdk has an attached delta.vmdk it should be possible to use dd against the flat.vmdk even if the VM is in use.
To troubleshoot unexpected behaviour check if any automatic backuptool has mounted the flat.vmdk

[jspiel]

So, the VM is in use, but there is a snapshot and a -delta.vmdk file, so it "should" work.

No backup tool is used during my tests.

If i shut down the VM, i don't have the error anymore.

[continuum]

Check wether flat.vmdk is locked with lsof

send via iphone

[jspiel]

[root@XServe3-ESXi:~] lsof |grep ZeusSrv-flat

281135      vmx                   FILE                       82   /vmfs/volumes/55785226-1e682e1a-0f8c-001e52f3e01c/ZeusSrv/ZeusSrv-flat.vmdk

[root@XServe3-ESXi:~] esxcli vm process list

ZeusSrv

   World ID: 281136

   Process ID: 0

   VMX Cartel ID: 281135

   UUID: 56 4d 66 f3 34 97 8a 64-d5 22 9f c1 89 bc 57 bb

   Display Name: ZeusSrv

   Config File: /vmfs/volumes/55785226-1e682e1a-0f8c-001e52f3e01c/ZeusSrv/ZeusSrv.vmx

[root@XServe3-ESXi:~] grep vmdk /vmfs/volumes/XServe3-500SSD-1/ZeusSrv/ZeusSrv.vmx

scsi0:0.fileName = "ZeusSrv-000002.vmdk"