Hey all..
After doing a BIOS upgrade on my test hosts, I was finally able to get them to list FT as enabled.
When I right click a VM and turn FT on, I am getting an error..
"Unsupported virtual machine configuration for fault tolerance. The unused disk blocks of the virtual machine's disks have not been scrubbed on the file system. This is needed to support features like Fault Tolerance."
When I power the VM off and turn on FT, it begins to scrub the VM's disks... this takes a long time.
Can someone explain to me exactly why it needs to do this? Just trying to understand the technology...
How can a disk be made thick-eager zeroed by default? ie. can this be done to my template?
Yes, use the datastore browser to inflate the disk in question.
What are the advantages/disadvantages of being thick-eager zeroed, rather than just thick?
An eager-zeroed thick disk has all space allocated and zeroed out at the time of creation. This extends the time it takes to create the disk, but results in the best performance, even on first write to each block.
Hello. VMware FT requires virtual machines to have thick-eager zeroed disks. Thin or sparsely allocated disks will be converted to thick-eager zeroed when VMware FT is enabled. Sounds like your disks were not thick-eagered for this particular VM.
How can a disk be made thick-eager zeroed by default? ie. can this be done to my template?
What are the advantages/disadvantages of being thick-eager zeroed, rather than just thick?
How can a disk be made thick-eager zeroed by default? ie. can this be done to my template?
Yes, use the datastore browser to inflate the disk in question.
What are the advantages/disadvantages of being thick-eager zeroed, rather than just thick?
An eager-zeroed thick disk has all space allocated and zeroed out at the time of creation. This extends the time it takes to create the disk, but results in the best performance, even on first write to each block.
All good to know. Thanks for your time!
No problem. You can also check out the vSphere Availability Guide for additional information on FT.
Good Luck!
From the vSphere availability guide. "When you turn on Fault Tolerance, the conversion to the appropriate disk format is performed by default. The virtual machine must be in a powered-off state to take this action"
I ran in to this same situation in my lab when I was trying to FT enable my Virtual Center VM. I got around it without taking the machine offline by Storage VMotioning the disks around and choosing "Think format".
Keith Chambers
Technical Marketing Engineer
Cisco
vExpert
"I ran in to this same situation in my lab when I was trying to FT
enable my Virtual Center VM. I got around it without taking the machine
offline by Storage VMotioning the disks around and choosing "Think
format".
Keith Chambers
Technical Marketing Engineer
Cisco
vExpert"
I tried that, I'm basically doing the same thing I am trying to get my secondary Vcenter server added as a fault tolerant host but its getting the disk needs to be zerod out error. The odd thing for me is I have powered off the Vm and enabled FT and it zeroed out the disks (it took FOREVER) but even after completing I still get the error. I have VMotiioned it from hos tto host and put it in diffrent dataq stores using the thick format option and I am still getting theerror.
Ran into same situation and after researching it on vmwares guides I found this answer.
You have attempted to turn on FT on a powered-on virtual machine which has thick formatted disks with the property of being lazy-zeroed. FT cannot be enabled on such a virtual machine while it is powered on. Power off the virtual machine, then turn on FT and power the virtual machine back on. This changes the disk format of the virtual machine when it is powered back on. Turning on FT could take some time to complete if the virtual disk is large.
I fixed mine by dooing as it said in this document and FT was able to be turned on for my vm. It does take a while depending how big your disk is.
I believe what caused this for my vm was it was provisioned from a thin template as a thick vm. I have other vm's that were never provisioned from this template and ft truns on just fine for them.
James Craft
JC Data Consulting LLC