Before purchase, is 3 guest OS with automatic core reassignment possible?

[TheBeardedQuack]

Hi all,

 

I'm looking at using unRaid to RAID my HDDs and also run multiple OS's at the same time on a single machine as demonstrated repeatedly on YouTube by LTT. If this is a pipe dream then I'm fine with dropping it and just having a decent RAID setup for a single OS but I'm curious to see if it'll work.

 

I have a 4c8t Intel i7-4790k and want to set it up in the following manor.

Core 1: dedicated to unRaid.

Core 2: dedicated to a 24/7 running LAMP Server.
Core 3: dynamic (wanted behaviour defined below).

Core 4: dynamic.

Dynamic behaviour (if even possible):

• If two Windows 10 instances running, one core each.
• Else if one Windows 10 instance running, both cores used for this instance
• Else add both cores onto the LAMP instance.

 

Ideally the core count would be able to change without the guest OS being restarted but I imagine this is highly unlikely, so the LAMP can be fixed at 1 core to prevent it needing to be restarted, the Windows instances are okay to be restarted when required. I understand this is somewhat of a ridiculous setup.

 

Thoughts / comments / suggestions?

[SSD]

1 hour ago, TheBeardedQuack said:

Hi all,

 

I'm looking at using unRaid to RAID my HDDs and also run multiple OS's at the same time on a single machine as demonstrated repeatedly on YouTube by LTT. If this is a pipe dream then I'm fine with dropping it and just having a decent RAID setup for a single OS but I'm curious to see if it'll work.

 

I have a 4c8t Intel i7-4790k and want to set it up in the following manor.

Core 1: dedicated to unRaid.

Core 2: dedicated to a 24/7 running LAMP Server.
Core 3: dynamic (wanted behaviour defined below).

Core 4: dynamic.

Dynamic behaviour (if even possible):

• If two Windows 10 instances running, one core each.
• Else if one Windows 10 instance running, both cores used for this instance
• Else add both cores onto the LAMP instance.

 

Ideally the core count would be able to change without the guest OS being restarted but I imagine this is highly unlikely, so the LAMP can be fixed at 1 core to prevent it needing to be restarted, the Windows instances are okay to be restarted when required. I understand this is somewhat of a ridiculous setup.

 

Thoughts / comments / suggestions?

 

You cannot dynamically adjust the cores assigned to a VM. I'm pretty sure the guest OS (Windows) would not support that. And KVM does not.

 

What you CAN do is this. You can have two different VM configurations that point to the same underlying vm image. And each VM configuration can have a different number of CPUs. (Remember, it is running the same VM, just using two different VM templates in unRAID). That would give you the flexibility to adjust the number of CPUs. (You would never want to try running both configurations at the same time!)

[TheBeardedQuack]

11 minutes ago, SSD said:

 

You cannot dynamically adjust the cores assigned to a VM. I'm pretty sure the guest OS (Windows) would not support that. And KVM does not.

 

What you CAN do is this. You can have two different VM configurations that point to the same underlying vm image. And each VM configuration can have a different number of CPUs. (Remember, it is running the same VM, just using two different VM templates in unRAID). That would give you the flexibility to adjust the number of CPUs. (You would never want to try running both configurations at the same time!)

 

I had a feeling that this would be how it would have to work, which is fine.
Is it possible to modify the configuration (or load one of the 3 config files [0, 1, 2 Windows instances ]) without shutting down the LAMP server?

So the configurations would be like this:

• Common to all config files:
  • Core 1: unRaid
  • Core 2: LAMP
• Config 1:
  • Core 3 & 4: Idle
• Config 2:
  • Core 3 & 4: Windows instance #1
• Config 3:
  • Core 3: Windows instance #1
  • Core 4: Windows instance #2

So when I want to swap configurations I'd have to safely shut down all Windows instances but I'm hoping I can leave the LAMP server running. Would the "live" configuration change be possible in unRaid?

[JonathanM]

58 minutes ago, TheBeardedQuack said:

So when I want to swap configurations I'd have to safely shut down all Windows instances but I'm hoping I can leave the LAMP server running. Would the "live" configuration change be possible in unRaid?

Yes, assuming your hardware is capable. Video cards and other i/o that you may want to pass through don't all support soft reset, so passed through assets may not properly come back up. If you are talking headless with remote access for all the VM's, then yes, it will work with no issues. I routinely start and stop multiple different VM instances without ever needing to reboot the host.

 

VM passthrough hardware is tricky, best to research and find someone who has done what you want to do successfully, and copy their list of hardware. Otherwise, you are probably going to run into issues that may be tricky to diagnose, and could be impossible to fix without purchasing different hardware.

[SSD]

3 hours ago, jonathanm said:

Yes, assuming your hardware is capable. Video cards and other i/o that you may want to pass through don't all support soft reset, so passed through assets may not properly come back up. If you are talking headless with remote access for all the VM's, then yes, it will work with no issues. I routinely start and stop multiple different VM instances without ever needing to reboot the host.

 

See below. YMMV.

 

Quote

VM passthrough hardware is tricky, best to research and find someone who has done what you want to do successfully, and copy their list of hardware. Otherwise, you are probably going to run into issues that may be tricky to diagnose, and could be impossible to fix without purchasing different hardware.

 

I will disagree slightly. I do think that the motherboard support for passthrough of video cards is very good. Not a slam dunk that it will work on any motherboard, but I'll go out on a limb and say 90% with ACS override (with I've used very successfully on two separate motherboards). USB passthrough of motherboard ports is a little less sure because the USB controllers are not always isolated. But worst case, you can use an add on PCIe USB controller. Bottom line, finding a motherboard someone else is using is smart, but if you've found a motherboard you want to use and don't have anyone saying they had trouble, I would move forward so long as you can return it in the unlikely situation it does not work.

[TheBeardedQuack]

9 hours ago, SSD said:

Bottom line, finding a motherboard someone else is using is smart, but if you've found a motherboard you want to use and don't have anyone saying they had trouble, I would move forward so long as you can return it in the unlikely situation it does not work.

 

I won't be looking for a new motherboard as I already have a full system and I'm just looking to make it work more for me. I can't find anything on lime-tech forum for the Gigabyte B85-HD3, I guess knowing that at least it's possible (albeit hardware dependant) I may as well give it a try once my additional SSD's turn up. Even if I can't get this setup I'll probably use unRaid anyway for Windows alone with the SSD's in RAID-0.

It's a shame that the motherboard for the "server" machine I have doesn't support USB boot (it's old) because I'd love to use unRaid on that too in RAID-1/5/10, but I guess software backups will do for now.

In case anyone knows something I can't find, the main system info is:

• Motherboard: Gigabyte B85-HD3
• CPU: Intel i7-4790k
• GPU: Nvidia Geforce GTX 1080, Gigabyte Turbo OC
• Memory: 4x8GB DDR3 @ 1600MHz
• Potential drives:
  • 3x Kingston SSD-Now V400 240GB (2 in RAID-0 for Windows #1 and 1 for LAMP)
  • 2x Kingston SSD-Now V300 240GB (2 in RAID-0 for Windows #2)
  • 1x 2TB 7200rpm HDD (can't remember make) (Split in partitions of 1TB/1TB, for windows programs)
  • 1x 2TB 5400rpm HDD (can't remember make) (Used entirely for media)

Before someone points out that the motherboard only has 6 SATA slots, I know... I'll either be using a PCIe expansion (as I also have a DVD-RW) or having a shifty around with the drives to make it 6.

[SSD]

3 hours ago, TheBeardedQuack said:

Before someone points out that the motherboard only has 6 SATA slots, I know... I'll either be using a PCIe expansion (as I also have a DVD-RW) or having a shifty around with the drives to make it 6.

 

The LSI SAS9201-8i is a good and inexpensive add on card. About $50 on eBay. 8 more ports.

 

3 hours ago, TheBeardedQuack said:

It's a shame that the motherboard for the "server" machine I have doesn't support USB boot (it's old) because I'd love to use unRaid on that too in RAID-1/5/10, but I guess software backups will do for now

 

There is a way to boot unRaid from a hard disk. Basically you have the USB attached, and after boot unRaid will find the USB and use it for all the configurations / plug-ins / Dockers.

 

You'd have to manually set up the hard disk, and keep it updated with each unRaid update.

 

There is a space invader one video that explains how to do this to set up an unRaid VM. There is actually a better way to do that, but the technique you'd use to boot of the hard disk is very similar and the video would get you started.