On Sat, Jul 13, 2024 at 8:50 PM Rick Macklem <[email protected]> wrote: > > On Sat, Jul 13, 2024 at 8:19 PM Garrett Wollman <[email protected]> > wrote: > > > > <<On Sat, 13 Jul 2024 19:42:32 -0700, Rick Macklem <[email protected]> > > said: > > > > > # ps axHl > > > should show you what wchan's the processes are waiting on and that might > > > give you a clue w.r.t. what is happening? > > > > zfs is waiting to write into the pipe and pv (the progress meter) is > > waiting in select. > Just to clarify it, are you saying zfs is sleeping on "pipewr"? If I am reading the code correctly, if it sleeping on "pipewr", it is out of space and that is controlled via: kern.ipc.maxpipekva and you can see what it is using by looking at kern.ipc.pipekva (Unfortunately, I don't think you can change kern.ipc.maxpipekva on the fly. It looks like it is a loader tunable, so you'd need to reboot to make it larger.)
Anyhow, you can take a look at the sysctls. They might help? There is quite a detailed comment in sys/kern/sys_pipe.c related to this. rick > (There is also a msleep() for "pipbww" in pipe_write().) > > rick > > > > > > If is easy to build a kernel from sources and boot that, you could try > > > defining > > > PIPE_NODIRECT in sys/kern/sys_pipe.c and see if that avoids the hangs? > > > > It's easy to build a kernel from sources, but not easy to reboot the > > server -- it's being retired shortly, and because of time constraints > > I need to get it drained before the next scheduled outage. > > > > -GAWollman > >
