VirtIO-FS Sent In For Linux 5.4 With Better Performance Over VirtIO-9P

[pal666]

It's also worth noting that you need to install Samba to use this option. If VirtIO-FS is in the kernel, I assume it will be much better in every possible way.

virtio-fs is not in windows guest's kernel, while smb is

[oiaohm]

Samba has issues when it comes to mapping permissions. It's also worth noting that you need to install Samba to use this option. If VirtIO-FS is in the kernel, I assume it will be much better in every possible way.

The problem with mapping permissions does not go away. Virtio-fs provides a Linux permissions model not a windows one. So this would require windows driver side to be able to talk cleanly Linux permissions.

As you stated samba is not perfect. The incompatibility between the two permission systems of Linux and Windows is basically not 100 percent solvable. Samba code base contains decades of work to make the permission mapping as good as they can be. So your assume having windows support virtio-fs would be better in every possible way is wrong. It would be horrible as windows in the virtual machine would have to work out how to talk Linux permissions. As we see with virtio-9p done by Microsoft for windows they don't have this worked out even with 9p limited subset of permissions possible under Linux. Virtio-fs using fuse in the Linux kernel is not a limited subset its the complete box and dice all the permissions Linux file systems can hold.

Really windows need to walk before it can run here. When windows can do virtio-9p with sanity then we can move on to virtio-fs. Even so samba on host still looks good as you can avoid stalling the windows vm out in the processing of the windows file system driver due to the fact samba running on the Linux host can do the house keeping stuff to be emulating windows permissions without stalling the windows kernel in the vm.

Permission differences between operating systems cause serous trouble.

[Guest]

The problem with mapping permissions does not go away. Virtio-fs provides a Linux permissions model not a windows one. So this would require windows driver side to be able to talk cleanly Linux permissions.

I was talking about it being better for proper operating systems. Watered down ones, like Windows make sense to be second class citizens.

[starshipeleven]

Storage these days is cheap and computers often come with more ports than you know what to do with. I personally just opt for a dedicated drive for my VMs. That way, you don't have to worry about drivers or additional overhead, in theory (haven't tested this) you could still boot from bare-metal, and you can access the files directly from the host (preferably not while the guest is still running). Any time I'm in need of files that regularly need to be accessed between the host and guest while both are running, I use a NAS. All of this can be done very affordably at home.

Your setup is significantly more expensive and less mobile than a single laptop with a SSD, while not being significantly better. Just because you have a lot of ports, it does not mean that using them all is better.

Also wtf is "I use a NAS". What is preventing you from sharing a folder from the host directly with Samba/SMB (aka the host is also the NAS)

[oiaohm]

I was talking about it being better for proper operating systems. Watered down ones, like Windows make sense to be second class citizens.

The permission problems exist between BSD and Linux as well. Reason why we have seen stat features extended a few times in Linux and BSD to attempt to address the differences but even then all the differences are not addressed yet.

Windows one is worse because its history goes back to VMS and that hardware. To be excutable on the VMS hardware you also had to be readable.

Linux and BSD goes back to Unix history some of that hardware had executeable that could not read. Yes the fun XnR (execute no read)

https://i.blackhat.com/briefings/asia/2018/asia-18-Zhang-Liu-Xom-switch--v1.3.pdf

That is being talked about being a modern security feature is old historic thing imprinted in the posix standard.

[schmidtbag]

Your setup is significantly more expensive and less mobile than a single laptop with a SSD, while not being significantly better.

No, not really. I paid $200 for my home server. I paid $350 for my laptop. My phone was about $40 (new). If accounting for the price of all the parts being new, my gaming PC would've been around $600. My hackintosh was made entirely of spare parts, most of which I didn't buy.
I spent less money for all of my devices combined than what some people spend on just a phone. Sure, none of them have impressive specs, but for my workloads, they all keep up.

Just because you have a lot of ports, it does not mean that using them all is better.

Ironically, my server is the only thing that doesn't have enough ports. I needed to add in a separate RAID controller.

Also wtf is "I use a NAS". What is preventing you from sharing a folder from the host directly with Samba/SMB (aka the host is also the NAS)

Do you not know what a NAS is or are you just being deliberately obtuse? My server (which BTW, isn't just a NAS) runs at about 15W when idle and is accessible over the internet. I'm not leaving my gaming PC on 24/7, my hackintosh doesn't make for a good server, and I'm not going to go on a tirade about the problems of using a laptop as a primary form of storage.

So no, my setup is not more expensive, it is actually more mobile than you think, and there are actually real benefits vs using a laptop with a big SSD.

[starshipeleven]

No, not really. I paid $200 for my home server. I paid $350 for my laptop.

Boom, right there 200$ that you could have saved by just setting up a shared folder on the laptop. We are talking of just running a VM here.

My phone was about $40 (new).

Is that a Dumbphone? (a non-smarphone phone). Not relevant for running VMs.

Do you not know what a NAS is or are you just being deliberately obtuse?

I'm just pointing out that, for the sole scope of sharing files between a host and a guest, having a separate NAS or server is beyond overkill.

My server (which BTW, isn't just a NAS) runs at about 15W when idle and is accessible over the internet.

Pfft, amateur.

Mine idles at around 100W but it's a dual-socket Fujitsu xeon rack with 256GB RAM and 16 2.5'' 600GB SAS drives (that apparently you can buy in batches of 20 at 100 euros or less on ebay).

I'm actually running the VMs directly on this server and connect to it from my much weaker PC through a dirt cheap 10Gb fiber connection (seriously, it's mind boggling how cheap are these things if compared to 10Gb copper-based cards).

But I'm not here posting on a forum about how it is so much more convenient to use a 2U rack server with all VMs and the storage I need inside of it, instead of just sharing folders between host and guest.

Because it makes no sense. I use this thing for my specific workload, while most people are fine with filesharing between host and guest in VMs.

I'm not going to go on a tirade about the problems of using a laptop as a primary form of storage.

There is this thing called external USB 3.0 hard drives. That's what sane people with a laptop keep their data in, and where everyone that cares about his data keeps a secondary backup in even if he has a NAS or server.

You can usually passthrough USB drives to the VM directly too, it's very convenient.

So no, my setup is not more expensive, it is actually more mobile than you think, and there are actually real benefits vs using a laptop with a big SSD.

Sorry no it is more expensive than sharing a local folder if all you need is sharing between VM and host.

Your setup exists for more than just passing files from VM to host I hope. That's the difference.

[schmidtbag]

Boom, right there 200$ that you could have saved by just setting up a shared folder on the laptop. We are talking of just running a VM here.

No it isn't, dumbass. You do realize that SSD storage gets a lot more expensive once you're in the TB range, right? I have my laptop for the sake of portability, so getting multi-TB HDDs containing most of my important info sounds like a real bad idea.
HDD is not an ideal choice if you want to maximize battery life. Using a pair of HDDs in RAID is a lot cheaper. Since my server does more than just share files, that $200 cost has already paid for itself better than a larger SSD in my laptop.

Is that a Dumbphone? (a non-smarphone phone). Not relevant for running VMs.

No actually, it's a quad core with 1GB of RAM running Android 8.

I'm just pointing out that, for the sole scope of sharing files between a host and a guest, having a separate NAS or server is beyond overkill.

You are so caught up in disagreeing with me that you totally failed to understand the point of my post, while also completely ignoring the fact I said that I prefer to use a dedicated drive for a VM. Even on a laptop, that would be doable, since USB 3.0 drives are compact, fast, and cheap.
Like I said, a NAS is typically a preferable option when you have files that you need accessible to multiple systems. If you only have 1 PC in your entire network then sure, there's no point of a NAS. But at that point you can just simply ignore my suggestion; it's not wrong like you seem to suggest it is. I'm sure many people who care about sharing data between a VM and its host are likely to want to share that data with multiple PCs. Having a dedicated system for that is, in many cases, easier and cheaper to work with.

Pfft, amateur.

Mine idles at around 100W but it's a dual-socket Fujitsu xeon rack with 256GB RAM and 16 2.5'' 600GB SAS drives (that apparently you can buy in batches of 20 at 100 euros or less on ebay).

And how exactly does that make me an amateur? My server does everything I need while sipping power. Why would I waste my money buying a server overkill for my needs?

I'm actually running the VMs directly on this server and connect to it from my much weaker PC through a dirt cheap 10Gb fiber connection (seriously, it's mind boggling how cheap are these things if compared to 10Gb copper-based cards).

So basically you're just taking my idea and going 1 step further with it. Hypocrite.

But I'm not here posting on a forum about how it is so much more convenient to use a 2U rack server with all VMs and the storage I need inside of it, instead of just sharing folders between host and guest.

Yeah, except my home server is almost completely silent, doesn't crank up my electric bill, is more convenient to access remotely, and takes up less space than a table lamp.
So, how about you stop jumping to more conclusions than you already have?

There is this thing called external USB 3.0 hard drives. That's what sane people with a laptop keep their data in, and where everyone that cares about his data keeps a secondary backup in even if he has a NAS or server.

That is sooo 2010. Nobody with modern systems use flash drives anymore to copy files to other systems.

You can usually passthrough USB drives to the VM directly too, it's very convenient.

Not if you want to access that data with multiple systems simultaneously.

Sorry no it is more expensive than sharing a local folder if all you need is sharing between VM and host.

If that's all you're doing then yes. But as I've already established, what I mentioned is a possible idea. It's not like I said a NAS is the only logical route, which for whatever reason you seem to think.

Your setup exists for more than just passing files from VM to host I hope. That's the difference.

If I were to make strictly a NAS, I could build one for less than $200.