Date: Tue, 04 Sep 2018 03:26:13 +0000 From: bugzilla-noreply@freebsd.org To: standards@FreeBSD.org Subject: [Bug 231129] The ZFS installer sets atime=off by default Message-ID: <bug-231129-99-YZ8HqCCFDb@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-231129-99@https.bugs.freebsd.org/bugzilla/>
index | next in thread | previous in thread | raw e-mail
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=231129 Allan Jude <allanjude@FreeBSD.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |allanjude@FreeBSD.org --- Comment #1 from Allan Jude <allanjude@FreeBSD.org> --- There is infact a good reason to disable atime. ZFS is a CoW (Copy-on-Write) filesystem, so when the atime property is set to on, all snapshots will grow as the atime attribute of each object is modified. This causes what are supposed to be zero-cost snapshots to resume space, and causes read-only workloads to generate amplification as additional metadata must be read for it to be updated to be written out with a modified atime and the checksum of the entire tree of blocks to be updated. The 'zfs auto' part of the installer sets atime on ZFS to disabled on purpose, for all datasets other than /var/mail. -- You are receiving this mail because: You are the assignee for the bug.home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?bug-231129-99-YZ8HqCCFDb>