Re: Potential CGD(4) bug

Greg Troxel <[email protected]> Mon, 25 May 2026 07:19:35 -0400
Newsgroups gmane.os.netbsd.general
Message-ID <[email protected]>
Sad Clouds <[email protected]> writes:

> I've been testing CGD + LVM combination with NetBSD-10.1 Bhyve VM and so
> far every single test reliably hangs the kernel. The same test with LVM
> only (i.e. no CGD) passes OK.
>
> The test involves intensive I/O to a single 40GiB file, using variable
> blocks between 1KiB - 32KiB and performed at random offsets. The user
> space threads performing I/O become stuck in tstile state:

Could you post a link to your test program?

What about cgd without lvm?

What about 10.1 on bare metal?

Any reason you are using 10.1 intead of the tip of netbsd-10?

You say bhyve, and I think you mean host/dom0 is FreeBSD using bhyve and
you have NetBSD 10.1 as a VM hosted on that.   Do you mean that, or
something else?   What do the virtual disks look like?

(Not claiming your suspicion that it points to cgd is wrong.)