VMware Solutions Discussions
VMware Solutions Discussions
Hello from Moscow!
There is a following problem.
After creation of a backup of VM (guest OS - Windows Server 2008 SP2), restoring of this VM occurs to an error: incorrect shut down of VM !!!
SnapManager 2.0 for VI with VMware vSphere 4.0 Update1 (build 208111) create snapshot of VM without flush of system memory VM to disk!
HOW TO CONFIGURE SMVI 2.0?
I have the same question .... Im starting to loose the point of existence of SnapManager for VI.
Given the following situation - 1 NFS Datastore with 1 VM on it. Machine is powered on, User is opening notepad and starting to write some text.
Scenario1 - im making SMVI backup of this VM (user still writing text). After restore of this machine (or whole datatstore no matter) VM is in powered off state and after power on i have "bad shutdown info" and a user has lost a whole notepad file.
Scenario2 - im making NetApp Snapshot of the volume containing VM (user is still writing text). After restore of this volume form snapshot machine is in powered off state and after power on i have "bad shutdown info" and a user has lost a whole notepad file.
Scenario3 - im making VMware Snapshot of this VM (user is still writing text). After snapshot revert user still has notepad open and i didnt lost any of the text which was input till the time of snapshot.
So my conclusion is:
- if using VMware snapshot i can get consistent backup why VMware snapshots made by NetApp are not giving same effect.
- if ther is no difference in effect (non concistent backup) between Scenario1 and 2 what is a purpose of SMVI and why pay for it??
Do i have something configured wrong or im I missong some point ? Any ideas?
NetApp SnapManager for Virtual Infrastructure addresses the resource utilization issue typically found within virtual environments by leveraging the underlying NetApp Snapshot technology , which enables you to create point-in-time copies of your virtual machines or entire data stores and then restore from these backup copies at any level of granularity— datastore, VM, disk (VMDK), or guest file —simply and quickly when required .This is all done on our storage systems, freeing your servers to run applications, not backups.
What happens in a backup process is that :
2. The VMware snapshot preserves the state of the virtual machine and is used by SMVI during
restores to revert the virtual machine back to the backup point-in-time state. VMware snapshots initiated by SMVI capture the entire state of the individual virtual machines,including disk and settings state; SMVI also gives users the option to disable VMware snapshots and just take a NetApp Snapshot copy on the volume underlying the datastore.
3. Once all the VMware snapshots have completed for a datastore, SMVI initiates a NetApp Snapshot copy on the volume underlying the datastore.
4. Upon completion of the NetApp Snapshot copy, SMVI removes the VMware vCenter snapshot to reduce space and performance overhead. Although the vCenter snapshot is removed within
vCenter, one VMware snapshot is maintained within the backup for each virtual machine that was
in a powered-on state. This snapshot is maintained so it can be used by the restore process to
evert the virtual machine to its point-in-time state.
5. Upon completion of the local backup, SnapManager for Virtual Infrastructure updates an existing
SnapMirror relationship on the volume underlying the datastore if the SnapMirror option was
selected. SnapMirror is discussed in further detail in a later section of this document.
SMVI doesn't quiesce memory during the Vmware snapshot operation.
When you take the VMware snapshot, if you
a) uncheck the "Snapshot the virtual machine memory"
b) check the "Quiesce guest file system'
You get the same behavior as SMVI.
We had some debate on whether there are any advantages in snapshotting virtual machine memory.
The conculsion was that it doesn't make sense.
Let us know if you think otherwise.
From the guest’s point of view, restoring to a memory snapshot results in all network connections being dropped and system timer jumping forward a few weeks. This is not the environment in which major production applications are normally tested, and so memory snapshots won’t be a supportable solution because this will likely trigger errors in apps.
Yeah this sounds reasonable - this explains why NetApp dont support "vm memory snapshots".
Thank you all guys for answers.
my 2 cents:
Memory snapshots are only senseful to be used during reverts of running vms. They provides memory and cpu status to revert to the exact position created by snapshot.
It's not possible to use a memory snapshot in a dr-scenario, because a powered-off vm isn't able to use an existing memory snapshot during power on.
From a VDI point of view however, this sort of restore could be very useful. You'd gain the ability to restore the users VM, and whatever applications they had running in that exact state at that point in time. That would be very powerful and useful for VDI.
But yes, for any other enterprise application, this would be useless and probably do more damage than good. Besides, you should be protecting your application data by other means.
Yeah exactly - VMware View was my test scenario. I agree that in server environment memory snaps are not soo good but in Virtual Desktops scenario this works like charm. It would be nice to have an option in SMVI to create different types of VMware Snapshots including memory.