Virtual Memory

[Archangel83]

Hi My question should be a simple one but im confused should i let the system manage my VM or should i set the numbers my self? Another question i have is it better to run the VM on the system disk or a second slave drive? here is a screen shot of what i have going on now.

 

[H2SO4]

Hi My question should be a simple one but im confused should i let the system manage my VM or should i set the numbers my self? Another question i have is it better to run the VM on the system disk or a second slave drive? here is a screen shot of what i have going on now.

1) Leave the default settings unless you have some particular reason to change them.

2) Both drives. The OS "knows" which disk is least busy at any given point in time, and it'll use the corresponding pagefile.

 

[whs]

Trying to outsmart the system is usually not a good idea. Unless you know a lot more than the hordes of programmers that developed the system, I would keep my hands off.

 

[jimbo45]

Hi there
Paging as prev poster says leave as default - the OS usually knows best.

However I'll disagree about the VM.

If the host is relatively inactive whilst you are doing your work in the VM then IT REALLY DOESN'T MATTER WHERE YOU HAVE THE VM.

The biggest bottleneck a VM has on home type computers is RAM - VM's need oodles and oodles of RAM once you start running serious apps on them.

Remember ALL RAM you allocate to a VM is permanently allocated to the VM and NOT available to the host.

What will happen when the host runs out of memory is not excessive paging per se - it will happen later read on.

A a FAR worse phenomenon known as SWAPPING will occur. This will try and write the ENTIRE virtual machines address space to disk and Swap in the host's memory requirement.

There won't be enough memory in the HOST to do this operation so paging will increase so much that the disk light will be hard on and your computer will appear to have locked up -- this is called "thrashing".

If you are running a VM don't over allocate RAM to it and when using the VM don't have any or at least minimal activity on the host. There isn't a 1:1 relationship in the requirements for a REAL to Virtual machine.

So it really doesn't matter on what disk you allocate the VM - put it on the fastest if I were you.

Cheers
jimbo

 

[whs]

Hi there
Paging as prev poster says leave as default - the OS usually knows best.

However I'll disagree about the VM.

If the host is relatively inactive whilst you are doing your work in the VM then IT REALLY DOESN'T MATTER WHERE YOU HAVE THE VM.

The biggest bottleneck a VM has on home type computers is RAM - VM's need oodles and oodles of RAM once you start running serious apps on them.

Remember ALL RAM you allocate to a VM is permanently allocated to the VM and NOT available to the host.

What will happen when the host runs out of memory is not excessive paging per se - it will happen later read on.

A a FAR worse phenomenon known as SWAPPING will occur. This will try and write the ENTIRE virtual machines address space to disk and Swap in the host's memory requirement.

There won't be enough memory in the HOST to do this operation so paging will increase so much that the disk light will be hard on and your computer will appear to have locked up -- this is called "thrashing".

If you are running a VM don't over allocate RAM to it and when using the VM don't have any or at least minimal activity on the host. There isn't a 1:1 relationship in the requirements for a REAL to Virtual machine.

So it really doesn't matter on what disk you allocate the VM - put it on the fastest if I were you.

Cheers
jimbo

This is an excellent point. I originally allocated 2GBs for my Win7 virtual partition (using vBox). That left 1.25GBs for my host Vista (4GB RAM in 32bit). BAAD news. My Vista was only creeping along whilst my Win7 hardly used 500MBs. Then I reduced the virtual partition to 1GB which leaves 2.25GBs for the Vista host. Now both systems perform very well and I hardly notice any impact on the Vista host. Just at the very beginning after opening the virtual partition it needs a little time for superfetch to rearrange the real estate. But that is minor.

 

[Archangel83]

ok first thank you all for your responses. now about drive speed how do i figure out what one of my 2 drives is the faster is their a tool in windows or is their a freeware program that could tell me that info? as for default settings win7 had the virtual memory on the system disk i only changed it to my slave disk as i once was told that having the vm on a different drive other then the os disk would increase performance this being said should i switch it back to the os disk or leave it on my slave ?

 

[Antman]

This thread is seriously derailed. The OP seems to be mislabeling the page file as VM (virtual memory). Jimbo is discussing Virtual Machines.

How 'bout them Cowboys?!

 

[whs]

This thread is seriously derailed. The OP seems to be mislabeling the page file as VM (virtual memory). Jimbo is discussing Virtual Machines.

How 'bout them Cowboys?!

Aha, I think you are right. But the other discussion was useful too. A real Babylon.

 

[H2SO4]

ok first thank you all for your responses. now about drive speed how do i figure out what one of my 2 drives is the faster is their a tool in windows or is their a freeware program that could tell me that info? as for default settings win7 had the virtual memory on the system disk i only changed it to my slave disk as i once was told that having the vm on a different drive other then the os disk would increase performance this being said should i switch it back to the os disk or leave it on my slave ?

What Antman said. Jimbo's advice pertained to a different definition of "VM", not the pagefile settings you're discussing.

If you're looking to make the best possible use of that second drive for pagefile purposes, don't just move the entire pagefile. Instead, split it up across both drives - say 2GB on the first drive, 2GB on the second, and so on for any new drives (spindles) you add to the system in the future.

 

[MacGyvr]

Hi there
Paging as prev poster says leave as default - the OS usually knows best.

However I'll disagree about the VM.

If the host is relatively inactive whilst you are doing your work in the VM then IT REALLY DOESN'T MATTER WHERE YOU HAVE THE VM.

The biggest bottleneck a VM has on home type computers is RAM - VM's need oodles and oodles of RAM once you start running serious apps on them.

Remember ALL RAM you allocate to a VM is permanently allocated to the VM and NOT available to the host.

What will happen when the host runs out of memory is not excessive paging per se - it will happen later read on.

A a FAR worse phenomenon known as SWAPPING will occur. This will try and write the ENTIRE virtual machines address space to disk and Swap in the host's memory requirement.

There won't be enough memory in the HOST to do this operation so paging will increase so much that the disk light will be hard on and your computer will appear to have locked up -- this is called "thrashing".

If you are running a VM don't over allocate RAM to it and when using the VM don't have any or at least minimal activity on the host. There isn't a 1:1 relationship in the requirements for a REAL to Virtual machine.

So it really doesn't matter on what disk you allocate the VM - put it on the fastest if I were you.

Cheers
jimbo

Ummm, the OP was not talking about a Virtual Machine....he was talking about Virtual Memory.

 

[sup3rsprt]

Ummm, the OP was not talking about a Virtual Machine....he was talking about Virtual Memory.

Ummm maybe you need to take Antman off ignore....because he already pointed that out

 

[Archangel83]

ok first thank you all for your responses. now about drive speed how do i figure out what one of my 2 drives is the faster is their a tool in windows or is their a freeware program that could tell me that info? as for default settings win7 had the virtual memory on the system disk i only changed it to my slave disk as i once was told that having the vm on a different drive other then the os disk would increase performance this being said should i switch it back to the os disk or leave it on my slave ?

What Antman said. Jimbo's advice pertained to a different definition of "VM", not the pagefile settings you're discussing.

If you're looking to make the best possible use of that second drive for pagefile purposes, don't just move the entire pagefile. Instead, split it up across both drives - say 2GB on the first drive, 2GB on the second, and so on for any new drives (spindles) you add to the system in the future.

So i should not just have the virtual memory/page file on just one disk but split it between all the disks in my machine? sorry if i made confusion about running a virtual machine I'm a noob/novice and get my definitions mixed up in the future i will remember the different acronyms

 

[H2SO4]

So i should not just have the virtual memory/page file on just one disk but split it between all the disks in my machine?

Yes. When multiple spindles are available, there are performance benefits to splitting up the pagefile across most or all of them. The OS has the ability to pick the instantaneously fastest (least busy) drive at a given point in time.

However, it won't make any huge difference for a home machine with a decent amount of memory. In fact, I'd be surprised if you actually noticed any effect.

sorry if i made confusion about running a virtual machine I'm a noob/novice and get my definitions mixed up in the future i will remember the different acronyms

No need to be sorry. It was a simple misunderstanding

 

[Antman]

sorry if i made confusion about running a virtual machine i'm a noob/novice and get my definitions mixed up in the future i will remember the different acronyms

no need to be sorry. It was a simple misunderstanding

iirc, irdm - af aik. Wamm. Ymmv.

Ftw.

 

[H2SO4]

iirc, afaik, irdm. Wamm. Ymmv.

Ftw.

OTOH, not all TLAs have equal SNAFU powers. E-TLAs tend to be more unique, while S-TLA usage more frequently results in FSCK-ups.

 

[Antman]

Who started this? Speak English.

 

[Archangel83]

HAHAHA! very funny

 

[whs]

iirc, afaik, irdm. Wamm. Ymmv.

Ftw.

OTOH, not all TLAs have equal SNAFU powers. E-TLAs tend to be more unique, while S-TLA usage more frequently results in FSCK-ups.

Hey guys, please have merci with us poor foreigners that so not understand your morse code - LOL.

 

[H2SO4]

iirc, afaik, irdm. Wamm. Ymmv.

Ftw.

OTOH, not all TLAs have equal SNAFU powers. E-TLAs tend to be more unique, while S-TLA usage more frequently results in FSCK-ups.

Hey guys, please have merci with us poor foreigners that so not understand your morse code - LOL.

"Inlining" Antman's post:

The Image and Identity Reseach Collective, as far as he knows, leads to Insulin Resistant Diabetes Mellitus. Thankfully, Women are Against Military Madness. Your Massive Mastodon ate my Velociraptor.

Quite.

 

[whs]

OTOH, not all TLAs have equal SNAFU powers. E-TLAs tend to be more unique, while S-TLA usage more frequently results in FSCK-ups.

Hey guys, please have merci with us poor foreigners that so not understand your morse code - LOL.

"Inlining" Antman's post:

The Image and Identity Reseach Collective, as far as he knows, leads to Insulin Resistant Diabetes Mellitus. Thankfully, Women are Against Military Madness. Your Massive Mastodon ate my Velociraptor.

Quite.

Thanks for the translation - very funny.