Date: Thu, 27 Dec 2018 11:24:20 +0100 From: Willem Jan Withagen <wjw@digiware.nl> To: Peter Eriksson <peter@ifm.liu.se>, freebsd-fs@freebsd.org Subject: Re: Suggestion for hardware for ZFS fileserver Message-ID: <362ced1c-f39e-cc6d-cf50-aab878c6cd49@digiware.nl> In-Reply-To: <3160F105-85C1-4CB4-AAD5-D16CF5D6143D@ifm.liu.se> References: <CAEW%2BogZnWC07OCSuzO7E4TeYGr1E9BARKSKEh9ELCL9Zc4YY3w@mail.gmail.com> <C839431D-628C-4C73-8285-2360FE6FFE88@gmail.com> <CAEW%2BogYWKPL5jLW2H_UWEsCOiz=8fzFcSJ9S5k8k7FXMQjywsw@mail.gmail.com> <4f816be7-79e0-cacb-9502-5fbbe343cfc9@denninger.net> <3160F105-85C1-4CB4-AAD5-D16CF5D6143D@ifm.liu.se>
next in thread | previous in thread | raw e-mail | index | archive | help
On 21/12/2018 19:53, Peter Eriksson wrote: Thanx, for the introduction to a serious platform running ZFS. Always interesting to read what other do with their sstuff. :-D But this can be "easily" fixed for the moment. > First thing we noticed was that booting would take forever… Mounting the 20-100k filesystems _and_ enabling them to be shared via NFS is not done efficient at all (for each filesystem it re-reads /etc/zfs/exports (a couple of times) befor appending one line to the end. Repeat 20-100,000 times… Not to mention the big kernel lock for NFS “hold all NFS activity while we flush and reinstalls all sharing information per filesystem” being done by mountd… > > Wish list item #1: A BerkeleyDB-based ’sharetab’ that replaces the horribly slow /etc/zfs/exports text file. > Wish list item #2: A reimplementation of mountd and the kernel interface to allow a “diff” between the contents of the DB-based sharetab above be input into the kernel instead of the brute-force way it’s done now.. > > (I’ve written some code that implements item #1 above and it helps quite a bit. Nothing near production quality yet though. I have looked at item #2 a bit too but not done anything about it.) It would be possible to not user /etc/zfs/exports. The syntax that can be inserted in that file through zfs itself is not quite flexible enough. I remember patching it, and then not getting this accepted, because it was too FreeBSD specific. So I started using /etc/exports. But cram all in /etc/exports, and only load and export files once zfs has loaded all its filesystems. Only speeds up so much, but keeps a few bottlenecks out of the equation. --WjW
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?362ced1c-f39e-cc6d-cf50-aab878c6cd49>