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Subject: Re: plan9 semantics on Linux - mount namespaces
To:     Aleksa Sarai <asarai@suse.de>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Linux Containers <containers@lists.linux-foundation.org>
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From:   Enrico Weigelt <lkml@metux.net>
Organization: metux IT consult
Message-ID: <9c097fd9-3035-d5be-a829-fc18e7734f18@metux.net>
Date:   Wed, 14 Feb 2018 10:18:13 +0000
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On 14.02.2018 04:54, Aleksa Sarai wrote:

> It depends how old your kernel is and what distro you use. Arch Linux > disables user namespaces entirely, Debian requires that you set a 
sysctl> to enable unprivileged user namespaces, and RHEL requires you to 
set> both a sysctl and a kernel boot-flag. Also check how old your 
kernel is> (unprivileged user namespace support was added in 3.8).
Just tried on a mainline kernel (4.15). Same problem:

root@alphabox:~ unshare -U -r
unshare: unshare(0x14000000): Invalid argument


root@alphabox:/proc/sys/user cat max_user_namespaces
5922


Am I missing something ?


--mtx

-- 
Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
info@metux.net -- +49-151-27565287