[BBLISA] Fwd: Re: Fileserver opinion

[Edward Ned Harvey]

> From: bblisa-bounces at bblisa.org [mailto:bblisa-bounces at bblisa.org] On
> Behalf Of Ian Stokes-Rees
> 
> With no significant experience administering NFS servers on anything
> other than Linux, does it really make sense to consider OpenSolaris, or
> a *BSD variant?  I.e. will the performance/reliability gains outweigh
> the
> pain/overhead of a new OS?

This is a very wise question.  It's true that the learning curve to get into
solaris/opensolaris is very significant if you're only familiar with linux.
However, the answer is yes.  It's absolutely worth while.  I went through
this exercise approx 1 year ago, and I'll tell you about it:

* ZFS does snapshots.  
* Users are able to restore their files instantly from snapshots, without
any assistance.
* Thanks to snapshots, when you do incremental backups, there is no need to
walk the tree, scanning for timestamp changes.  The filesystem already has a
list of all the blocks which changed on disk, and it's able to instantly
stream those blocks to the destination.  This shortened my nightly backup
window from 10 hrs to 10 mins on a 1TB filesystem.
* If you build a ZFS pool out of some spindle disks, and some SSD's, you're
able to put all the sync-mode writes (latency sensitive) onto the SSD's, and
all the async-mode writes onto the spindles.  Async writes are buffered in
ram and therefore many small operations are aggregated into a single large
operation.  This increases performance by a factor of ... I would say 5x or
10x.
* All block operations are checksummed automatically in the filessytem.  If
a checksum mismatch is encountered (all hardware makes errors) then the
other redundant copy in mirror or raid is used instead.  Auto-detection and
correction of errors, which would have passed corrupt and undetected in
linux.  It is surprising how often this happens.

Linux can do none of these things, until BTRFS is stable.

I wouldn't recommend opensolaris.  I'd recommend solaris 10.  You can
download & use sol10 on a trial basis for free, but if you put it into
production, you want to pay for support.  I get mine from Dell for $400/yr.