Snapshot takes a long time in VMware Fusion 12 Pro

[RafaelVega]

Hello Support VMware.

Why does snapshots in VMware Fusion take a long time to complete when the virtual machine is powered on?

I currently have a Mac Book Pro 15¨ 2019 (i9 CPU - 32 GB RAM - 1 TB SSD) and also a iMac 27¨¨ 2020 (i9 CPU - 128 RAM - 1 TB SSD). In both I have VMware Fusion 12 Pro installed.

Every time I take a snapshot of any powered virtual machine (Window, Linux, etc.), it takes more than 10 minutes to finish snapshoting completely (Very slow snapshot process).

Waiting 10 minutes every time I take a snapshot, this is very tedious for me. I am one of the VMware Fusion users who needs to take a quick snapshot before making changes to my virtual machine lab.

I have compared the snapshot times between VMware Fusion 12 Pro and Parallels 16 Pro, and found that the snapshot process in Parallels is very fast.

What adjustment needs to be made in VMware Fusion 12 Pro to make snapshots faster?

Note: Shutting down the virtual machine, then taking the snapshot and then turning the virtual machine back on, is NOT an option for me. This is not a solution.

Regards.

Rafael Vega.

[scott28tt]

How many CPUs and how much memory are allocated to your various VMs?

[RafaelVega]

Hi Scott,

I took several evidences of the virtual machines, which I specify below. Also, I took the time to snapshot each virtual machine (One virtual machine powered on at a time).

VM1: Windows Server 2019 DataCenter - 8 CPU Cores - 10 GB RAM - 60 GB SSD.

Snapshot time (Min): 12:10.

VM2: Windows 10 Professional - 4 CPU Cores - 4 GB RAM - 60 GB SSD.

Snapshot time (Min): 6:10.

VM3: Kali Linux 2020.1a - 4 CPU Cores - 4 GB RAM - 20 GB SSD.

Snapshot time (Min): 6:26.

VM4: FortiGate Virtual Firewall v1723 - 1 CPU Cores - 2 GB RAM - 30 GB SSD.

Snapshot time (Min): 3:16.

VM5: Cisco Router CSR1000V - 4 CPU Cores - 6 GB RAM - 16 GB SSD.

Snapshot time (Min): 9:44.

Waiting for your information.

Regards,

Rafael Vega.

[ColoradoMarmot]

Some other questions:

- what's the configuration of the host?

- are you on an SSD, a Fusion Drive, or a spinning disk?

- Do you have time machine disabled for the virtual machines?

[RafaelVega]

Hi dlhotka

I answer your questions:

- what's the configuration of the host?

Mac Book Pro 15¨ 2019 (i9 CPU - 32 GB RAM - 1 TB Apple SSD NVMe)

iMac 27¨¨ 2020 (i9 CPU - 128 RAM - 1 TB Apple SSD NVMe).

- are you on an SSD, a Fusion Drive, or a spinning disk?

I am using Apple SSD NVMe internal hard drive.

- Do you have time machine disabled for the virtual machines?

Time Machine is disabled on both computers.

Waiting for your information.

Regards,

Rafael Vega

[ColoradoMarmot]

Ok, so first of all, 8 cores is too many.  Any individual guest should have no more than N-1 (where is is physical cores) assigned.  On my 16" MBP (8 cores), practically speaking I find that if I have guests running with more than 6 cores or so between them, performance degrades.

On the internal drive, time machine/snapshots can't be disabled completely, so if you're tight on disk space, dumping 8GB+ RAM images can take a while, as the snapshot cleanup takes time to run.  Might be worth trying on a fast external SSD to see if that helps.

[RafaelVega]

Hi dlhotka,

Thanks for your answer. I clarify the following, since I think that the possible solutions you say are not adequate:

"Ok, so first of all, 8 cores is too many.  Any individual guest should have no more than N-1 (where is is physical cores) assigned.  On my 16" MBP (8 cores), practically speaking I find that if I have guests running with more than 6 cores or so between them, performance degrades".

Answer: This is not the solution.

• Virtual machines have only one physical CPU, but with the possibility of assigning several cores to it.
• Saying that only 1 core to a virtual machine is very poor performance (Only Windows 10 requires a minimum of 2 Cores. And you are telling me to only assign 1 Core).
• My MBP 15 & iMac 27 2020 computers have not performance degradation. Nor are the virtual machines experiencing performance degradation.
• If you noticed in the previous information on this forum, I have virtual machines with different numbers of Cores assigned, and in all of them there is slowness when making a Snapshot.

On the internal drive, time machine/snapshots can't be disabled completely, so if you're tight on disk space, dumping 8GB+ RAM images can take a while, as the snapshot cleanup takes time to run.  Might be worth trying on a fast external SSD to see if that helps.

Answer: This is not the solution.

• Do I have two high-performance Apple computers so that I now have to use an external SSD?
• Additionally I tested Parallels 16 Pro on the same Apple computers, with the same resources assigned to the virtual machines (1, 4 and 8 Cores), and Parallels spanshots are super fast.
• Why does Parallels work fine and Fusion doesn't?

I searched various forums for this problem. Even on YouTube I observed several users reporting the slowness of VMware Fusion when taking a snapshot.

Regards,

Rafael Vega.

[ColoradoMarmot]

I never said 1 core.  The rule is N-1 cores to any individual VM, where N is the number of physical cores in the system.  On a 6-core CPU that means no more than 5 to any individual VM.

This is a user to user forum, with people volunteering to help.  Given your response, I'll stop trying.  Good luck.

[RickShu]

Hi RafaelVega,

Just want to confirm with you, when you say 'it takes more than 10 minutes to finish snapshoting completely', is the VM still usable during the process?

Regards,

-Rick

[RafaelVega]

Hi Rick,

Así es Rick. The virtual machine is usable during the snapshot. Let me show you something (This is the behavior):

1. The order is given to execute a snapshot with the virtual machine turned on.

2. This is where the snapshot takes a long time.

During the snapshot, I can continue to use the virtual machine; however, I understand that I must wait for the snapshot to finish completely to be sure of making critical internal VM modifications.

Regards,

Rafael Vega.