topic Re: Machines get corrupted after every power loss in ESXi Discussions

Machines get corrupted after every power loss

brnogu — Wed, 08 Apr 2020 13:02:21 GMT

Hello everyone!

After some searches online I was not able to find an answer to my issue. On every power loss on my vSphere machine all the guests get corrupted and it's necessary to perform a repair to the .vmdk file through ssh.

This is a small home server and it's very frequent that it experiences power loss. I was using Hyper-V before and never had this corruption problems.

What do you think could be the issue? The corrupt every single time there's a power loss.

Version: 6.7.0 Update 3 (Build 15160138)

Thank you

Re: Machines get corrupted after every power loss

vFouad — Wed, 08 Apr 2020 16:46:13 GMT

Could you share a little more about the storage hardware?

Is it just a single local spinning drive?

Is it a raid array?

What do you mean by repair the vmdk? Please be as specific as possible.

Kind regards,

Fouad

Re: Machines get corrupted after every power loss

brnogu — Thu, 09 Apr 2020 00:22:26 GMT

Hi vFouad

Thank you for your reply. This is a small asus computer running a single SSD drive, no RAID configured.

To repair de vmdk file I've followed the instructions on this website: https://www.vionblog.com/vmware-6-5-cant-start-vm-host-crash/

Hardware details:

Thanks!

Re: Machines get corrupted after every power loss

continuum — Thu, 09 Apr 2020 16:29:34 GMT

If you have powerfailures regularly you either need automatic daily backups - or you need to radically reduce the amount of thin provisioning you use.

If you configure your VMs as eager zeroed thick provisioned and dont use snapshots then VMFS is not fragile any more.

Re: Machines get corrupted after every power loss

brnogu — Thu, 09 Apr 2020 16:34:25 GMT

Hi continuum

Thank you for your reply. So it means that if I have a eager zeroed it will not be fragile anymore (aka not getting corrupted after every power loss) but I lose the ability to make snapshots. Is this correct?

Is there a way to convert the vmfs file?

Super Thanks!

Re: Machines get corrupted after every power loss

continuum — Thu, 09 Apr 2020 16:55:55 GMT

No - you can still use snapshots.
But snapshots are thin provisioned and thats what makes them fragile.

Re: Machines get corrupted after every power loss

continuum — Thu, 09 Apr 2020 16:57:36 GMT

Yes - to convert your thin.vmdk into a eagerzeroedthick use

vmkfstools -i thin.vmdk eagerzeroed.vmdk -d eagerzeroed

Re: Machines get corrupted after every power loss

brnogu — Thu, 09 Apr 2020 17:01:07 GMT

Super thanks for your help! :smileygrin:

Have a nice day and Stay Safe!

Re: Machines get corrupted after every power loss

vFouad — Thu, 09 Apr 2020 17:04:22 GMT

One other thing that may be playing into this issue, is your hardware.

I'm assuming you are using a commercial grade SSD not an enterprise grade ssd...

Commercial grade SSD's are not battery backed so sudden power failures means that cache data is not properly destaged.

This would be your source of corruption.

It might be worth looking into a small Uninterrupted Power Supply for that machine.

Kind regards,

Fouad