On Thu, Dec 28, 2017 at 12:03:12PM +0100, Didier Kryn wrote: > Le 27/12/2017 à 01:05, Hendrik Boom a écrit : > > As I understand it, there are a few new file systems somewhat > > available on Linux -- ZFS, XFS, and Btrfs. > > I have tried btrfs; it still runs on a few servers I have installed. I'm > reluctant to continue with it because it is too tied to RedHat/Systemd
Funny that: I'd strongly recommend not using btrfs and systemd together; it is also very unfriendly to Red Hat's kernel mess. Caveats include: * systemd won't ever mount degraded raid from fstab, as boot device, etc, even if you explicitly request -o degraded. * on manual degraded mounts, systemd will maliciously unmount it! Your only hope is to "mount;cd" and hope to win the race (you'll usually do), after which systemd's attempt to unmount will fail. * long-running processes such as scrub will get killed when you log out the session that spawned them (disabled by default on Debian, enabled on Red Hat). Balance survives this (ignores SIGKILL), scrub will finish its in-kernel parts then fail to write the result. > I prefer to use mdadm for RAID - different tools for different tasks. MD is drastically weaker than btrfs raid: * it can save you only from errors detected by the disk. And in case resync /check finds a discrepancy, it has no way to repair it: it doesn't know which copy is the good one. * it can do only two equal-sized disks (or three or more, but you won't get extra capacity). Btrfs can take any number of disks of unequal sizes, and will fully utilize the capacity unless one disk is bigger than the sum of the rest. > I partially agree whith what has been said about RAID: it is > essentially meant to ensure high availability. It doesn't provides all we > expect from backup: it does not protect against human errors or malevolent > actions; yet it is a protection against the consequences of disk failure. True. Raid improves your uptime and protects from short-term errors (no data loss between last backup and failure), but is no substitute for backup. For a typical server, you need both. Meow! -- // If you believe in so-called "intellectual property", please immediately // cease using counterfeit alphabets. Instead, contact the nearest temple // of Amon, whose priests will provide you with scribal services for all // your writing needs, for Reasonable And Non-Discriminatory prices. _______________________________________________ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
