Bug#944661: nfs-kernel-server: Please support specifying ionice-ness

[Diederik de Haas]

Package: nfs-kernel-server
Version: 1:1.3.4-2.5
Severity: wishlist

Once can already specify nice-ness through RPCNFSDPRIORITY which sets
the --nicelevel parameter of start-stop-daemon.
But I want to also specify the ionice-ness and start-stop-daemon already
supports that through the --iosched parameter.
It would be great if that was enacted through /etc/init.d/nfs-kernel-server
invocation and preferably set via /etc/default/nfs-kernel-server file.

-- Package-specific info:
-- rpcinfo --
program vers proto port service
100000 4 tcp 111 portmapper
100000 3 tcp 111 portmapper
100000 2 tcp 111 portmapper
100000 4 udp 111 portmapper
100000 3 udp 111 portmapper
100000 2 udp 111 portmapper
100024 1 udp 57068 status
100024 1 tcp 36259 status
100003 3 tcp 2049 nfs
100003 4 tcp 2049 nfs
100227 3 tcp 2049
100003 3 udp 2049 nfs
100227 3 udp 2049
100021 1 udp 55374 nlockmgr
100021 3 udp 55374 nlockmgr
100021 4 udp 55374 nlockmgr
100021 1 tcp 39865 nlockmgr
100021 3 tcp 39865 nlockmgr
100021 4 tcp 39865 nlockmgr
100005 1 udp 46446 mountd
100005 1 tcp 39125 mountd
100005 2 udp 51891 mountd
100005 2 tcp 52869 mountd
100005 3 udp 38839 mountd
100005 3 tcp 45117 mountd
-- /etc/default/nfs-kernel-server --
RPCNFSDCOUNT=8
RPCNFSDPRIORITY=-10
RPCMOUNTDOPTS="--manage-gids"
NEED_SVCGSSD=""
RPCSVCGSSDOPTS=""
-- /etc/exports --
/srv/backup/ 192.168.1.0/24(rw,no_root_squash,no_subtree_check)
/srv/media/ 192.168.1.0/24(ro,no_root_squash,no_subtree_check)
-- /proc/fs/nfs/exports --
# Version 1.1
# Path Client(Flags) # IPs

-- System Information:
Debian Release: 10.1
APT prefers stable
APT policy: (990, 'stable'), (500, 'stable-updates'), (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.19.0-6-amd64 (SMP w/16 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)
LSM: AppArmor: enabled

Versions of packages nfs-kernel-server depends on:
ii keyutils 1.6-6
ii libblkid1 2.33.1-0.1
ii libc6 2.28-10
ii libcap2 1:2.25-2
ii libsqlite3-0 3.27.2-3
ii libtirpc3 1.1.4-0.4
ii libwrap0 7.6.q-28
ii lsb-base 10.2019051400
ii netbase 5.6
ii nfs-common 1:1.3.4-2.5
ii ucf 3.0038+nmu1

nfs-kernel-server recommends no packages.

nfs-kernel-server suggests no packages.

-- no debconf information

[Diederik de Haas]

In the initial bug report, you can see that /etc/default/nfs-kernel-server has
RPCNFSDPRIORITY=-10

But I don't think that has the intended effect, because all the nfsd processes
have a priority of 0, not -10.

I tried a local path to implement ionice-ness.

Added to /etc/default/nfs-kernel-server
# Runtime IO priority of server (see ionice(1) and start-stop-daemon(8))
# Value is class[:priority]
# class values: real-time, best-effort (default), idle
# priority values: 0-7 (only for realtime and best-effort) (default: 4),
optional
# default RPCNFSDIOPRIORITY=best-effort:4
RPCNFSDIOPRIORITY="real-time:0"

And changed /etc/init.d/nfs-kernel-server to
start-stop-daemon --start --oknodo --quiet \
--nicelevel $RPCNFSDPRIORITY \
--iosched $RPCNFSDIOPRIORITY \
--exec $PREFIX/sbin/rpc.nfsd -- $RPCNFSDCOUNT

(i.e. added --iosched line)

but requesting the ionice-ness of the nfsd processes showed it wasn't applied
either.

I don't know (yet?) whether this is an issue with s-s-d or the init script.

[Ben Hutchings]

Control: tag -1 wontfix

On Wed, 13 Nov 2019 14:41:13 +0100 Diederik de Haas
<didi....@cknow.org> wrote:
> Package: nfs-kernel-server
> Version: 1:1.3.4-2.5
> Severity: wishlist
>
> Once can already specify nice-ness through RPCNFSDPRIORITY which sets
> the --nicelevel parameter of start-stop-daemon.
> But I want to also specify the ionice-ness and start-stop-daemon already
> supports that through the --iosched parameter.
> It would be great if that was enacted through /etc/init.d/nfs-kernel-server
> invocation and preferably set via /etc/default/nfs-kernel-server file.

[...]

I/O scheduling priority can already be set through systemd service
configuration. I don't anticipate adding any new features to the
Debian-specific init scripts.

Ben.

--
Ben Hutchings
It's easier to fight for one's principles than to live up to them.