[BBLISA] RE: storevault / netapp

[Edward Ned Harvey]

So correct me if I'm wrong, the basic setup that you're describing would be
... 

A bunch of disks, in the hardware level JBOD, with caching controller card
for performance sake.
Let the software handle the raid, lun, and FS expansion.

For production, go for the xstore, but for testing, I could go get any
standard cots white/black box, and install the free downloadable version of
solaris.

You got my curiosity juices flowing.


> -----Original Message-----
> From: robc at solarflares.net [mailto:robc at solarflares.net]
> Sent: Wednesday, February 27, 2008 1:44 PM
> To: Peter Galvin
> Cc: Edward Ned Harvey; Bblisa at Bblisa. Org
> Subject: Re: [BBLISA] RE: storevault / netapp
> 
> On Wed, 27 Feb 2008, Peter Galvin wrote:
> 
> > At the moment ZFS cannot expand a storage pool by single disk
> increments.
> > You could for example expand a RAIDZ pool by concatenating another
> RAIDZ set
> > to it, but not by adding a single disk.
> 
> Sure you can, "zpool add $poolname $device"
> 
> > On 2/27/08 11:44 AM, "Edward Ned Harvey" <bblisa2 at nedharvey.com>
> wrote:
> >
> > > The second one, what I'm referring to as "dualparity" is the
> ability to
> > > sustain 2 simultaneous disk failures without data loss.  This is a
> function
> > > of the hardware raid controller, and not the filesystem.  Am I
> making any
> > > bad assumptions here?  I am not aware of any hardware raid
> controllers that
> > > can safely lose two disks at the same time, except the
> > > netapp/storevault/other enterprise filers.  What I'm saying is,
> it's not
> > > supported like this on a sun xstore solaris zfs machine.  Right?
> 
> Definitely supports multiple simultaneous device failures.  We did our
> initial testing on "whitebox" systems/arrays, then decided to use
> xstore
> for production.
> 
> > > incrementally add disks, without degradation of redundancy or
> downtime.  If
> > > I've got 6 disks in a dualparity configuration, controlled by
> hardware DP
> > > raid (usable capacity of 4 disks assuming no hotspare), I just slap
> in one
> > > more disk, and increase the size of my FS by 25%.  No downtime, no
> > > degradation of redundancy.  Perhaps the system runs slow for a
> couple hours.
> > > This too is not supported in the sun xstore solaris zfs
> configuration,
> > > right?
> 
> Definitely supported, no need to recompute.
> 
> > > I don't think it's fair to say it's supported in OSX.  In OSX, you
> cannot
> > > format and create a ZFS filesystem, and you can only mount it read-
> only.
> > > Although read/write variations exist, they are very immature at
> best.
> 
> You can definitely create a ZFS filesystem in OSX, as of Tiger I
> believe,
> can't say I run it daily, but we did a test just to qualify this
> feature.
> 
> > >
> > > Same is true for Linux.  Although it's open source, it can't be
> compiled in
> > > the linux kernel any time soon.  Because it's written under CDDL,
> which
> > > conflicts with GPL.  See here:
> http://en.wikipedia.org/wiki/ZFS#Platforms
> 
> Fair enough.  I don't really know much about Linux to be honest.
> 
> Also -- ZFS does not need battery backup to deal with hardware crashes
> mid-write.  There is a lengthy presentation out there which describes
> this
> in detail.
> 
> -rob
>