3 ms·

I believe it is still using virtio. Therefore, disk read/writes are not good enough compared to other virtualization tech such as qemu

by m00dy 7y ago

ctz 7y ago
> disk read/writes are not good enough This is an odd thing to say; surely that depends on the application? I doubt most FaaS users are disk IO-bound?
yjftsjthsd-h 7y ago
I thought virtio was higher performance; why would that make it "not good enough"?
JoshTriplett 7y ago
Which of qemu's many disk technologies are you proposing as an alternative?
detaro 7y ago
qemu setups often use virtio, afaik virtio was defined by qemu devs, so your statement doesn't really make sense without more details. Also, "not good enough" kind of needs a definition of a workload and what's "good enough" for it.
- bonzini 7y ago
  It's using virtio-mmio which is less efficient than virtio-pci. But I/O was not a focus of Firecracker, for example it doesn't scale very well because it doesn't do concurrent I/O operations.
StreamBright 7y ago
I am not sure if this is true. Well, you are not really making a statement that could be easily interpreted. Virtio is specifically created to address performance issues with virtualization. Are you unhappy about the implementation quality or you generally believe that para-virtualization is not the way to go about improving virtualization overhead? One prime example when with virtio it was possible to get native performance _after_ minimum configuration tuning: https://serverfault.com/questions/407842/incredibly-low-kvm-disk-performance-qcow2-disk-files-virtio https://serverfault.com/questions/407842/incredibly-low-kvm-... More details on virtio: https://vmsplice.net/~stefan/virtio-devconf-2014.pdf https://vmsplice.net/~stefan/virtio-devconf-2014.pdf
m00dy 7y ago
hello guys, I'm sorry that my first comment was not enough informative.Now, I'm refering to the paper that I read couple of days ago [0]. If you look at the figure 8-9, FC has some issues with IO. [0]: https://blog.acolyer.org/2020/03/02/firecracker/ https://blog.acolyer.org/2020/03/02/firecracker/

I believe it is still using virtio. Therefore, disk read/writes are not good enough compared to other virtualization tech such as qemu

by m00dy 7y ago

I believe it is still using virtio. Therefore, disk read/writes are not good enough compared to other virtualization tech such as qemu

ctz 7y ago

> disk read/writes are not good enough This is an odd thing to say; surely that depends on the application? I doubt most FaaS users are disk IO-bound?

yjftsjthsd-h 7y ago

I thought virtio was higher performance; why would that make it "not good enough"?

JoshTriplett 7y ago

Which of qemu's many disk technologies are you proposing as an alternative?

detaro 7y ago

qemu setups often use virtio, afaik virtio was defined by qemu devs, so your statement doesn't really make sense without more details. Also, "not good enough" kind of needs a definition of a workload and what's "good enough" for it.

bonzini 7y ago
It's using virtio-mmio which is less efficient than virtio-pci. But I/O was not a focus of Firecracker, for example it doesn't scale very well because it doesn't do concurrent I/O operations.

StreamBright 7y ago

I am not sure if this is true. Well, you are not really making a statement that could be easily interpreted. Virtio is specifically created to address performance issues with virtualization. Are you unhappy about the implementation quality or you generally believe that para-virtualization is not the way to go about improving virtualization overhead? One prime example when with virtio it was possible to get native performance _after_ minimum configuration tuning: https://serverfault.com/questions/407842/incredibly-low-kvm-disk-performance-qcow2-disk-files-virtio https://serverfault.com/questions/407842/incredibly-low-kvm-... More details on virtio: https://vmsplice.net/~stefan/virtio-devconf-2014.pdf https://vmsplice.net/~stefan/virtio-devconf-2014.pdf

m00dy 7y ago

hello guys, I'm sorry that my first comment was not enough informative.Now, I'm refering to the paper that I read couple of days ago [0]. If you look at the figure 8-9, FC has some issues with IO. [0]: https://blog.acolyer.org/2020/03/02/firecracker/ https://blog.acolyer.org/2020/03/02/firecracker/