I have 3 Fibre Channel SANs that I image my VMs to, that share storage with another ESXi host. The benefit of this is having an entire spare host that I can light up if anything happens to my primary hosts. I simply rename the backup%date% folder to Backups and all the backup VMs are pointed to their respective vmdks already in that folder. GhettoVCB, as opposed to trilead or veeam, allows me to FREELY image a running guest VM to this shared datastore on free esxi. As far as I know, there is no other way to do this at the cost of free. Veeam wants vcenter and trilead only lets you offload the VMs as disk files to your Local computer.
With that all being said, please don't grill me about my backup solution or methods, I have my reasons and up until now, they've been tried and true.
Out of my three fibre channel SANs, I have 6 giant RAID-0 arrays, 2 per box. I have two esxi hosts with 6 VMs per. Host A and Host B. All 12 VMs backup using a script I wrote to which ever datastore is next in rotation, allowing to have multiple copies of my datacenter if I need to revert back, etc.. Three of the VMs on Host A fail to backup successfully ever since upgrading all three hosts (Host A, Host B and my spare host) to Dell's latest rev of VMWARE 6.0 U1 (OCT '15). But, they only fail on one of the datastores out of the 6... I remember, even though the backup was set for thin disks, it said something about enabling vmkernel for 2gb sparse when it began. All three disks are OS disks that ghettovcb complains about. Two windows 2008 and one 2008r2. Even wierder, I used the p2v converter to re-image the smallest of the three failed VMs back to the host and it still fails...
My only assumption is that something to do with the block size of that datastore is causing an issue? I've nuked the software RAID and formatted the disks, still have the issue. I've changed the name of the backup folder and when I re-imaged the one VM with p2v, it even rename the disk file.. I want to say all disks involved have been "extended" a couple of times, but I'm not 100%. At least two of them have, though. When the hosts were 5.5, this datastore worked fine and the other 9 VMs would agree.
Datastore used to work, ESXi version changed, new ghettovcb script had to be downloaded from github. Still, the script works on the same host, different datastores. Just not this one in particular. UGH!
I've rebooted all three hosts. I've reformatted the datastore using dd.