What happens if iSCSI fails

Question

Hyper-V

Comrades, please tell me:

I have a Hyper-V cluster with iSCSI storage, on which virtual machines lie. What happens if the link to storage disappears?

Is there some kind of timeout during which virtual machines will continue to work?

What happens after the timeout? Suspend or poweroff?

What will happen to the file system?

Answer 1

It is necessary to ask the oversan)))
it is obvious that suspension is impossible without storage.
I assume that there will be a lot of swearing in the system log, the machines will go into poweroffs with the effect of pulling the power plug out of the socket and the corresponding consequences.

Answer 2

You would write in the title that we are talking about Hyper-V.

Answer 3

I can describe from memory a similar situation in vSphere. If the connection to the storage is lost, then the virtual machines continue to work using the data in the host memory (for example, if a word processor is open, you can print in it, switch between windows). When you try to access data on the storage, the application goes into standby mode, as it were. When the connection is restored, the virtual machine restores work. Whether there is a recovery wait timeout or not, I don't know.

Answer 4

I checked it on the test, the result is:
Hyper-V 2012, iscsi 2008 r2, when the iscsi target is rebooted, the virtual machine continues to ping for ~ 20 seconds (depending on the equipment) and it works the same way. Then the "plug from the socket", as already mentioned.
Files are normal, as in a normal power failure.
Hyper-V does not restore the connection to iscsi itself, including the cluster (dispatcher) does not.
The Failover Clustering Manager starts to blunt, and on all nodes.
After 15 minutes, the dispatcher's work returns to normal, you can turn on the virtual machine in it, start live migration and issue the owner of the disk with it.