Re: Performance issues with /gnu/store in virtual machines

[Ludovic Courtès]

address@hidden (宋文武) skribis:

> address@hidden (Ludovic Courtès) writes:
>
>> Hi Chris,
>>
>> Christopher Baines <address@hidden> skribis:
>>
>>>   1.13    0.000019           0      3853           openat
>>
>> [...]
>>
>>>  13.56    0.193014          50      3853           openat
>>
>> So openat(2) is 4 orders of magnitude slower in the VM, which is a
>> problem.
>>
>> I guess a large part of that is due to the fact that VM created with
>> ‘guix system vm’ use unionfs as their root file system, which is a FUSE
>> thing (see the “volatile” options in (gnu system vm), (gnu system
>> linux-initrd), and (gnu build linux-boot).)  I’m not sure how we could
>> avoid it.
>
> We might switch to the linux kernel's bultin overlayfs, which should be
> faster.
>
> https://wiki.archlinux.org/index.php/Overlay_filesystem

Good point, we should probably do that.

Ludo’.