Unsolved pagefile size on Windows Server with dynamic RAM?
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@Mike-Davis said in pagefile size on Windows Server with dynamic RAM?:
Maybe I don't need crash dumps until the day the thing starts crashing and I need to figure out why... thoughts?
Also if you disable the dumps, you'd have nothing to investigate with ;-). So don't go turning them off...
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@Mike-Davis said in pagefile size on Windows Server with dynamic RAM?:
The system is set to "Automatic memory dump".
From that article:
The Automatic memory dump setting at first selects a small paging file size, would accommodate the kernel memory most of the time. If the system crashes again within four weeks, the Automatic memory dump feature selects the page file size as either the RAM size or 32 GB, whichever is smaller.So I guess I can set it to 6GB or something and then up it if it ever crashes. Thanks for the pointers.
You're welcome.
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@IRJ said in pagefile size on Windows Server with dynamic RAM?:
@Mike-Davis Check this article out.
Thanks. That was helpful as well.
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@Mike-Davis said in pagefile size on Windows Server with dynamic RAM?:
@IRJ said in pagefile size on Windows Server with dynamic RAM?:
@Mike-Davis Check this article out.
Thanks. That was helpful as well.
Basically you don't need a paging file.
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@IRJ said in pagefile size on Windows Server with dynamic RAM?:
@Mike-Davis said in pagefile size on Windows Server with dynamic RAM?:
@IRJ said in pagefile size on Windows Server with dynamic RAM?:
@Mike-Davis Check this article out.
Thanks. That was helpful as well.
Basically you don't need a paging file.
That is not at all what the article says...
Minimum PF should be large enough to cover the memory demands of your largest process. In the case of application allocating 50 MB of memory, the allocations request will fail with out of virtual memory error. When application allocates 10 MB chunks, the first two allocations will go through while the rest will fail as there’s no virtual memory (either RAM or PF) to accommodate that.Which is the same as saying scale appropriately, don't do something insane like committing 240GB to the PF (off the bat)
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@DustinB3403 said in pagefile size on Windows Server with dynamic RAM?:
@IRJ said in pagefile size on Windows Server with dynamic RAM?:
@Mike-Davis said in pagefile size on Windows Server with dynamic RAM?:
@IRJ said in pagefile size on Windows Server with dynamic RAM?:
@Mike-Davis Check this article out.
Thanks. That was helpful as well.
Basically you don't need a paging file.
That is not at all what the article says...
Minimum PF should be large enough to cover the memory demands of your largest process. In the case of application allocating 50 MB of memory, the allocations request will fail with out of virtual memory error. When application allocates 10 MB chunks, the first two allocations will go through while the rest will fail as there’s no virtual memory (either RAM or PF) to accommodate that.Which is the same as saying scale appropriately, don't do something insane like committing 240GB to the PF (off the bat)
With a properly configured host reserve, if you follow (Peak Commit Charge – Physical Memory + some buffer) formula on the host, you’ll find out that you don’t need a page file. -
@IRJ said in pagefile size on Windows Server with dynamic RAM?:
@DustinB3403 said in pagefile size on Windows Server with dynamic RAM?:
@IRJ said in pagefile size on Windows Server with dynamic RAM?:
@Mike-Davis said in pagefile size on Windows Server with dynamic RAM?:
@IRJ said in pagefile size on Windows Server with dynamic RAM?:
@Mike-Davis Check this article out.
Thanks. That was helpful as well.
Basically you don't need a paging file.
That is not at all what the article says...
Minimum PF should be large enough to cover the memory demands of your largest process. In the case of application allocating 50 MB of memory, the allocations request will fail with out of virtual memory error. When application allocates 10 MB chunks, the first two allocations will go through while the rest will fail as there’s no virtual memory (either RAM or PF) to accommodate that.Which is the same as saying scale appropriately, don't do something insane like committing 240GB to the PF (off the bat)
With a properly configured host reserve, if you follow (Peak Commit Charge – Physical Memory + some buffer) formula on the host, you’ll find out that you don’t need a page file.No that is page filing for the Host, not for the VM's.
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Think of it like this, separation of the hypervisor and VM's means a VM should never effect the host in terms of a VM crash. It's why separation is critical between the two, among the other issues.
This is purely at the VM level that needs to be targeted first. Then the Host must have it's own PF settings configured for the host. In case it crashes.
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OK I'm totally new to dynamic RAM assignment.
@Mike-Davis what do you gain by using Dymanic RAM assignment in this case, unless you're overallocating on the server? You mention that your RDS server can spike to 80 GB of RAM, do you find that the loss in performance when running less than that is worth using dymanic RAM (i.e. when you have to much RAM that's not in use on a VM, you can have performance issues on that VM).
This is an educational question for me.
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@Dashrender said in pagefile size on Windows Server with dynamic RAM?:
OK I'm totally new to dynamic RAM assignment.
@Mike-Davis what do you gain by using Dymanic RAM assignment in this case, unless you're overallocating on the server? You mention that your RDS server can spike to 80 GB of RAM, do you find that the loss in performance when running less than that is worth using dymanic RAM (i.e. when you have to much RAM that's not in use on a VM, you can have performance issues on that VM).
This is an educational question for me.
The point of the Dynamic RAM allocation is because he'll have peaks and valleys of users using the RDS system. Keeping the memory as static on any host is almost wasteful as other hosts could likely use the memory as well when they have to process reports or whatever else.
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@Dashrender said in pagefile size on Windows Server with dynamic RAM?:
OK I'm totally new to dynamic RAM assignment.
@Mike-Davis what do you gain by using Dymanic RAM assignment in this case, unless you're overallocating on the server? You mention that your RDS server can spike to 80 GB of RAM, do you find that the loss in performance when running less than that is worth using dymanic RAM (i.e. when you have to much RAM that's not in use on a VM, you can have performance issues on that VM).
This is an educational question for me.
@Dashrender That's a good question. Basically I have two RDS servers. A primary and then one that can be put in to service by just setting the IP address. The host doesn't have enough RAM for me to allocate them both the most RAM they would ever use, but by assigning dynamic RAM to them both, they can both be online and I can keep them patched up to date, etc. It was the fastest way I could think of to be able to put the second RDS server in to service should the primary one have an issue.
I'm open to suggestions if anyone has any other ideas.
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Do you already have a connection broker configured for these hosts?
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And the reason I ask about the connection broker, is you could just have both RDS servers going at the same time, and have the connection broker send the bulk of the connection request to your primary rds and if it hits a threshold, send the new incoming to the backup RDS server.
Since both are configured for dynamic ram allocation, this would be a better approach overall. Also it means you could take down an RDS server, and the connection broker would send all of the connection request to the backup RDS server.
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Why do you have two RDS servers on the same VM host? If it's because you only have one VM host and you want to be able to do patches while the system is up and running, I understand that.
In this case where you are bouncing live users from one VM to the other, I understand the use of Dynamic RAM.
I do like Dustin's suggestion on the broker though - but I'm not familiar enough with them to know if they can do what you want or not.
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@DustinB3403 No - There are a couple reasons. The main reason is that the two servers don't get patched at the same time and the app they are running doesn't get updated at the same time. This is so that if an update breaks the server, I can just put the other one in service. I suppose I could set up a connection broker and have all the request go to one or the other, but then that's another server to troubleshoot if something isn't working.
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The bottom line is that it's the software vendors patches and updates that are my biggest concern. Having a second server that is a version behind and ready to go is cheap protection against that.
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@Mike-Davis said in pagefile size on Windows Server with dynamic RAM?:
The bottom line is that it's the software vendors patches and updates that are my biggest concern. Having a second server that is a version behind and ready to go is cheap protection against that.
As @scottalanmiller would say the cheaper approach might be to find a new vendor / solution..
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So if these systems are on different patch cycles, and a patch breaks your primary RDS hosted application. I assume you use the backup as a fall in, and then perform a restore to the primary, or uninstall the patch to address the issue.
My question is there a way you can setup snap shotting at patch night, and if the patch breaks the system then you just restore the snap?
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@DustinB3403 Yes we can (and do) snap and we can restore snaps. The last time the server got hosed, we did just that. I think it 20 minutes total and the owner was impressed, but then the vendor needed to figure out how to move forward. That's when we built a second server for him to test his new version on.
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Seems like the fix should be on the Zabbix side.
