Suggestion for hardware for ZFS fileserver

[Willem Jan Withagen]

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