If you're running zfs tools in a container setting the timeout to 0 will likely be helpful. The device node will never appear in the containers /dev since a) it's a tmpfs and b) even if it were a devtmpfs it wouldn't help since devtmpfs isn't namespaced. (In fact udevd will even ignore any device event inside an unprivileged container since it's sent with INVALID_{G,U}ID. I have kernel patches to handle this and a bunch of other quirks that are up for merging.) For unpriv containers any device that you somehow create by talking to /dev/zfs (e.g. by having LXD create a device node for the container) will never show up in the container. It will always show up in the hosts devtmpfs.
On the host setting it to 0 should also not have a negative effect since the modprobe should a) cause devtmpfs to create the device node *before* sending a uevent and b) zfs userspace will likely wait for udevd to settle aka setup symlinks and persistent device naming. The timeout logic only makes sense for old udevd implementations that do create device nodes and might do so in a delayed manner. But better to test. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to zfs-linux in Ubuntu. https://bugs.launchpad.net/bugs/1760173 Title: zfs, zpool commands hangs for 10 seconds without a /dev/zfs Status in lxd package in Ubuntu: New Status in zfs-linux package in Ubuntu: Triaged Bug description: 1. # lsb_release -rd Description: Ubuntu 16.04.4 LTS Release: 16.04 2. # apt-cache policy zfsutils-linux zfsutils-linux: Installed: 0.6.5.6-0ubuntu19 Candidate: 0.6.5.6-0ubuntu19 Version table: *** 0.6.5.6-0ubuntu19 500 500 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages 100 /var/lib/dpkg/status 3. When inside a lxd container with zfs storage, zfs list or zpool status either return or report what's going on. 4. When inside a lxd container with zfs storage, zfs list or zpool status appears to hang, no output for 10 seconds. strace reveals that without a /dev/zfs the tools wait for it to appear for 10 seconds but do not provide a command line switch to disable or make it more verbose. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: zfsutils-linux 0.6.5.6-0ubuntu19 ProcVersionSignature: Ubuntu 4.13.0-36.40~16.04.1-generic 4.13.13 Uname: Linux 4.13.0-36-generic x86_64 ApportVersion: 2.20.1-0ubuntu2.15 Architecture: amd64 Date: Fri Mar 30 18:09:29 2018 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=C.UTF-8 SourcePackage: zfs-linux UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lxd/+bug/1760173/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp