Low Virtual Memory Condition on Azure B1ms VM

Question

_{Friday, December 7, 2018 8:03 PM}

Recently created a couple of Windows 2016 Standard B1ms (1 vcpus, 2 GB memory) to run IIS with a small set of applications and now getting these low memory warnings, which are news to me. I think this condition, may be related to a lack of actual memory that could've caused one of the applications to stop as well, although there is no "out of memory" event logged.

Here is view of task manager on the VM that stopped my application;

Here is the task manager on the twin VM (that didn't stop the application)

My question: Is there a configuration parameter that should be set to mitigate the "low virtual memory condition" and thus be sure that it is not affecting the running applications..?

Simone

All replies (9)

_{Monday, December 10, 2018 7:09 PM ✅Answered}

Dear George

Thanks very much for your response, and yes I agree the issues are related, although I didn't realise that at first. I worked out two resolutions over the last two days as follows;

1. The easy way: increase virtual memory on secondary VM as shown

After about 2 hours the VM had downloaded, installed the update and was waiting for a re-start, which took another 45 minutes to complete.

After that Windows Update was showing that "2018-11 Cumulative Update for Windows Server 2016 for x64-based Systems (KB4467691)" had installed successfully.

2. The hard way: manually download and update on primary VM

After Logging a support call, had four quite long phone conversations with an Azure tech, who RDP'd to the VM and carried out a manual update, pretty much as per suggestions in your troubleshooting post.

The above routine may not look much, but it took 1.5 hours to run. Tech will confirm this morning by RDP again that it indeed updated properly because it doesn't show in Windows Update. The VM is running ok.

This sort of technical activity is way beyond my ability, I'm an application person, I just want it to work.

Conclusion: The problem only came to my attention because my applications were falling over due to complete exhaustion of VM resources during multiple attempts to run a Windows Update. Ordinarily, these small VMs skip along very nicely with the 2Gb & SSD disks, updates happen in the background and no intervention is required.

It wasn't obvious the update and virtual memory issues were related until I spotted "TiWorker.exe" is "Windows Module Installer Worker" and one of the main culprits consuming virtual memory that wouldn't budge above 511mb even though it's meant to be managed by the system. Increasing it manually seemed to do the trick.

The temp VM update suggestion would likely have worked too, although I didn't need to try it in the end.

Cheers, Simone

_{Saturday, December 8, 2018 12:23 AM}

Just noticed that my brand new Azure B1ms VM has failed to load this update for nearly a month;

Question: Can someone please advise on how to get this installed..?

Thanks in advance

Simone

_{Sunday, December 9, 2018 7:57 PM}

Hi,

Sometimes it happens to me. I had to face a similar problem like that to a VM with low resources.

Something easily you can try is to change size to your VM, for an hour and try to update windows again.

You can also check this post for update troubleshooting. 

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_{Sunday, December 9, 2018 8:18 PM}

Hi, 

I think that 2 GB for a VM that you run IIS service is not enough.

Think that OS reserve almost 1GB and if we take as an assumption that you also connect with RDP, and at the same time you run IIS Server then I think that the solution in your problem is to change your VM size.

At least you can try it for testing purposes and see the difference.

If you have any update in your case, do not hesitate to answer in this post.

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_{Sunday, December 9, 2018 9:07 PM}

Thanks George, you may well be correct, however I've logged a support call to see what the Azure Team say.

In response to your comments;

1. It only runs the SMTP part of IIS and appears to only use about 8mb of memory (http is blocked)

2. It runs 3 powershell scripts, which as you can see use just under 170mb

3. I hardly ever RDP it except to update scripts, over 2 months in this case, which when I saw the failed update

Everything else is controlled from the Azure Portal. 

I'd expect a VM with practically nothing running on it to update itself without much problem, wouldn't you..?

Here is the Task Manager via RDP (both of which use a bit of memory but aren't running during an update)

Look what happens when it attempts to do the update!

The other issue that cropped up is the "Low Virtual Memory Condition" which may or may not be relevant.

Simone

_{Sunday, December 9, 2018 9:18 PM}

Thanks George

IIS doesn't appear to use much memory as only the smtp function is used (http is blocked), while my actual application uses only 1-200mb and could be stopped for an update. Maybe some of these Background and Windows processes could take a break to let an update happen.

I wonder if it is a simple as increasing the paging file on D: what do you think..?

Thought it would have already been optimised, but maybe not.

Simone

_{Monday, December 10, 2018 8:41 AM | 1 vote}

Hello Simone,

Exactly, this happens because the Windows module installer worker need more resources to finish the job.

If you upgrade the VM tier, this job will be finished sooner. And after it's done you can downgrade the VM tier.

Another solution is to install updates manually  from this address https://www.catalog.update.microsoft.com/Home.aspx

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_{Monday, December 10, 2018 8:48 AM | 1 vote}

Hi Simone,

I think that both forum posts are for the same incident. If not please correct me.

When you download and install the windows updates, probably your problem will solved.

The drive D: already used for the system page file, check this link for details.

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_{Monday, December 10, 2018 7:16 PM | 1 vote}

Hi Simone, 

I'm glad I help and your problem is solved.

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