Ok migration of W2K8R2 with 6.2 drivers from XCP-ng 7.5 to XCP-ng 7.5 failed with msg:
Storage_Interface.Does_not_exist(_)
It also crashed the VM.
I think this could be related to https://bugs.xenserver.org/browse/XSO-785 as there is only 10GB free on the source storage repository so I don't think I can actually do the migration because of that (it's recommended to have 2x space available to migrate a VM, something that becomes increasingly harder with large VMs!).
@Gheppy cool thanks. Good to see some real-world experience with a similar setup!
@olivierlambert Testing is a pain due to the resources required for this (!) and duplicating the setup, particularly as its something we were looking at as a proposal to the client atm.
I meant corruption could occur on boot up of the replicated VM as if it didn't have memory included then it would be booted like it had crashed effectively so there could be some corruption potentially from that effect.
Where does the saving of the memory occur to if its 180GB?! I.e. where do we need that 180GB of resource? Is the VM 'paused' whilst the memory is saved?
cheers
john
Hi,
We have a large Windows Server 2012R2 VM that comes in at 4.5TB of storage across several disks (largest disk is 2TB) and has 180GB of RAM. It runs SQL Server. We were wondering about whether we could enable continuous replication on this to speed up recovery times in a failure situation.
CR supports snapshot with memory - I was wondering what it has been tested to and if there is a limit to size on this and whether 180GB of RAM would end up being problematic if we wanted to do it hourly? 
Does 'normal' snapshot in this process do quiescing with VSS? I'm a bit nervous that if we can't do the memory CR then we'll end up with corrupted databases effectively when it boots up. Oh this is running on XenServer 7.0 still although I want to get it over to XCP-ng ideally.
Thanks,
John
@christopher-petzel Thanks for those tips. This seemed to work well on two Windows Server 2019 VM's, but not on a Windows 10 VM which sat there saying "Preparing Automatic Repair" for ages, so I reverted back to non-secure boot.
john
Hm.. I did a toolstack restart and it still had the high memory usage after, but it has now since dropped..
root 1920 0.2 2.0 108860 39516 ? Ssl Aug16 2:39 /usr/sbin/message-switch --config /etc/message-switch.conf
Perhaps it takes a bit of time to clear it out.
@olivierlambert said in XCP-ng 7.5.0 final is here:
Ah damn! I think you spotted the issue then!
I think that is different to the original problem as there was enough disk space in that instance, but this non-production VM I was using to test doesn't have the space on the source host.
New problem I've come across since doing that failed migration, the message-switch process is now eating approx half of the memory on the server:
[root@host log]# free -m
total used free shared buff/cache available
Mem: 1923 1601 27 12 295 221
Swap: 511 26 485
[root@host log]# ps axuww | grep message
root 1920 0.2 52.4 1094032 1033144 ? Ssl Aug16 2:36 /usr/sbin/message-switch --config /etc/message-switch.conf
root 32669 0.0 0.1 112656 2232 pts/24 S+ 12:43 0:00 grep --color=auto message
Anyone know how to restart that?
Ok migration of W2K8R2 with 6.2 drivers from XCP-ng 7.5 to XCP-ng 7.5 failed with msg:
Storage_Interface.Does_not_exist(_)
It also crashed the VM.
I think this could be related to https://bugs.xenserver.org/browse/XSO-785 as there is only 10GB free on the source storage repository so I don't think I can actually do the migration because of that (it's recommended to have 2x space available to migrate a VM, something that becomes increasingly harder with large VMs!).
ok, I've got one running XS 6.2 drivers I can test although it's got 100GB of disk so will take some time to do. Both ends are XCP-ng 7.5. I'll live migrate it and back with this driver first as a test and then try some others, see how it goes.
Edit: this vm is Win 2008R2 also where as previous which failed was 2K12.
@borzel unfortunately this is a production client server so can't do that easily. The two linux VM's moved over fine. Most of the VM's we have are Linux based also but I might be able to do it with an internal one on a different host but need to see if it can be moved easily as it has multiple network interfaces.
I think the one with the issue I mentioned before had XS7.1 drivers installed.