turn off 220V on UPS device =} file system got corrupted Re: Hyper-V 2012 Cluster / Failover - supported? - Any known issues?

Thu Sep 19 12:49:18 UTC 2013

Hi!

A.G.> if high availability failover scenarios will work for FreeBSD VMs on Hyper-V.
A.G.>if the power plug is pulled from the Hyper-V server then would the FreeBSD VM failover and restart without any 
issues on the failover server.

 Karl, are You want this behavior:
==
 you walk up and yank the power cord out of the back of the server the secondary mirror will take over with zero client 
downtime
==
or?
 Karl, are You use entry level fault tolerant system ftServer 2600 by Stratus Technologies? Or analog?

If "no use" , then read some info about real Hyper-V Fault Tolerance :

http://vvm.blog.tut.by/2013/09/19/fault-tolerant-solutions-for-hyper-v/

 Or vice versa,  for example:
===
Q:
I've got a two node server-cluster, Windows 20XX x64, Hyper-V and CSV, Everything seems to be working fine along with 
live migration.

I am currently testing the functionality of the setup, he is my current layout:

Node A:VM 1
Node B:VM 2

When I simulate a host failure on node A, VM 1 transfers over to Node B but reboots the virtual machine before bringing 
it back up.

Is this normal behavior for Clustering with CSV? I have another cluster setup in the same manner but without CSV 
enabled,

Its been a while but I'm sure when this was tested the Virtual machine that failed over didn't reboot.

Is this a difference between High availability and Fault tolerance?

  . . .

A:
there are third parties, such as Stratus, that create a mirrored environment between two systems in order to keep two 
copies up to date.

As you can imagine, there are additional costs involved in such a solution as this, so you need to make the business 
case for 100% availability.

==

>> When I simulate a host failure on node A, VM 1 transfers over to Node B but reboots
A.G.>  without any issues

Restart, but  _very_ often  with _big_ problem

Best regards, Victor Miasnikov
Blog:  http://vvm.blog.tut.by/

P.S.

 Even with Fault Tolerance remember about non-hardware issue:

http://blogs.msdn.com/b/clustering/archive/2010/10/06/10072013.aspx
==
FT solutions provide great resilience to hardware faults, such as if you walk up and yank the power cord out of the back 
of the server the secondary mirror will take over with zero client downtime.However, remember that FT solutions are 
running a common operating system across those systems.In the event that there is a software fault (such as a hang or 
crash), both machines are affected and the entire solution goes down.There is no protection from software fault 
scenarios and at the same time you are doubling your hardware and maintenance costs.At the end of the day while a FT 
solution may promise zero downtime for unplanned failures, it is in reality only to a small set of failure 
conditions.With a loosely coupled HA solution such as Failover Clustering, in the event of a hang or blue screen from a 
buggy driver or leaky application

==

----- Original Message ----- 
From: "Abhishek Gupta (LIS)"
To: "Victor Miasnikov"; "Karl Pielorz"; freebsd-virtualization freebsd.org
Sent: Wednesday, September 18, 2013 9:18 PM
Subject: RE: turn off 220V on UPS device =} file system got corrupted Re: Hyper-V 2012 Cluster / Failover - supported? - 
Any known issues?

Hi Victor,

Karl is asking if high availability failover scenarios will work for FreeBSD VMs on Hyper-V.
He was specifically interested in knowing
if the power plug is pulled from the Hyper-V server then would the FreeBSD VM failover and restart without any issues on 
the failover server.

My response was that yes the above scenario should work.
Thanks,
Abhishek

-----Original Message-----
From: Victor Miasnikov [mailto:vvm at tut.by]
Sent: Wednesday, September 18, 2013 8:46 AM
To: Abhishek Gupta (LIS); Karl Pielorz; freebsd-virtualization at freebsd.org
Subject: turn off 220V on UPS device =} file system got corrupted Re: Hyper-V 2012 Cluster / Failover - supported? - Any 
known issues?

Hi!

K.P.> - Pulling the power on the active node hosting both VM's (i.e. Windows K.P.> guest, and FreeBSD guest) - this 
showed the remaining node trying to bring K.P.> up the VM's (of which Windows came up OK, and FreeBSD [file system]  got 
corrupted).

A.G.> Yes, it should work.
A.G.>My understanding is that the failover should be agnostic to the guest OS but there could be some integration 
component that we might have missed.

 What _exactly_ "should work" ?

1)  This issue not related Hyper-V cluster itself
!)  When "Pulling the power" i.e. turn off 220V in Europa ( or 110V in USA ) on UPS device _both_  FAT on Windows and
FreeBSD [file system]  got corrupted

(  "Windows came up OK"  look like because on this VM file system is NTFS )

K.P.> Hyper-V correctly see's the node fail, and restarts both VM's on the
K.P.> remaining node. Windows 7 boots fine (says it wasn't shut down correctly -
K.P.> which is correct) - but FreeBSD doesn't survive.
K.P.>
K.P.> At boot time we get a blank screen with "-" on it (i.e. the first part of
K.P.> the boot 'spinner') - and nothing else.
K.P.>
K.P.> Booting to a network copy of FreeBSD and looking at the underlying virtual
K.P.> disk - it appears to be trashed. You can mount it (but it understandably
K.P.> warns it's not clean) - however, any access leads to an instant panic ('bad
K.P.> dir ino 2 at offset 0: mangled entry').
K.P.>
K.P.> Trying to run fsck against the file system throws up an impressive amounts
K.P.> of 'bad magic' errors and 'rebuild cylinder group?' prompts.

 To Karl: I ask You about some details . . .
Are You see related e-mail?

Best regards, Victor Miasnikov
Blog:  http://vvm.blog.tut.by/

----- Original Message ----- 
From: "Abhishek Gupta (LIS)"
To: "Karl Pielorz"
Sent: Wednesday, September 18, 2013 5:50 PM
Subject: RE: Hyper-V 2012 Cluster / Failover - supported? - Any known issues?

> Thanks again Karl! Yes, it should work.
>My understanding is that the failover should be agnostic to the guest OS but there could be some integration component
>that we might have missed.
>So it would be good to get to the bottom of this.
>
> Regards,
>
> Abhishek

 ________________________________________
> From: Karl Pielorz
> Sent: Wednesday, September 18, 2013 7:45 AM
> To: Abhishek Gupta (LIS);
> Subject: RE: Hyper-V 2012 Cluster / Failover - supported? - Any known issues?
>
> --On 18 September 2013 14:23 +0000 "Abhishek Gupta (LIS)"
> wrote:
>
>> Hi Karl,
>>
>> Thanks for reporting the issue. Please give us some time to investigate
>> and get back to you on this. In the meantime I wanted to ask if setting
>> up a Hyper-V replica for the FreeBSD VM and then a manual failover
>> reproduces the same symptoms? Please let me know.
>
> Hi,
>
> Manual fail-over appears to work OK - in order, I tested:
>
> - Live migration from one node to the other, and back again (worked)
>
> - Stopping the cluster service on one of the nodes (i.e. from Failover
> Cluster Manager) - this showed the VM moving from the node that was
> stopped, over to the other node (again worked).
>
> - Pulling the power on the active node hosting both VM's (i.e. Windows
> guest, and FreeBSD guest) - this showed the remaining node trying to bring
> up the VM's (of which Windows came up OK, and FreeBSD got corrupted).
>
>
> I've had to stop now as the guy here looking after the Synology kit on the
> test network is applying a firmware update (this is apparently for some
> appletalk issue or something).
>
> I'll re-run the test after this has been done - if it still fails, I'll
> come back with a 'how to reproduce' type report (and I'll obviously let you
> know if we can't reproduce it again!).
>
> At least I know it 'should' work now :)
>
> Thanks,
>
> -Karl