> From: [email protected] [mailto:[email protected]]
> On Behalf Of Adam Levin
> 
> Hoo, boy!  Great topic.  Full disclosure: a few years ago, I worked for
> NetApp for a year.  I no longer work for a vendor -- didn't care for the
> general atmosphere of having to believe that everything my company sold
> was the best at everything for everything.
> 
> That said, there is no question in my mind that I would choose NetApp NAS
> over EMC Celerra NAS in nearly every case.

Agreed fully about disbelieving the company line...
And I would personally choose Oracle/ZFS in nearly every case over the
Netapp.  ;-)

This is something I am seriously interested in ... I particpate a lot in ZFS
discussions, but I also don't believe the party line "ZFS is better at
everything for everything."  I am very interested to find ways in which
Netapp or anything else is better than ZFS.  I currently know only a very
small number of not very important things:

The .zfs/snapshot directory only exists at the parent level, which is not
quite as convenient as having the .snapshot subdirectory in every directory.

ZFS does storage tiering, but it's more along the lines of caching.  The
system chooses what will be in the various levels based on historical usage
patterns.  You don't get to choose or influence the balancing very much.  I
like more control knobs and gauges.

If you enable dedup, ZFS is a huge memory hog, as it does dedup live all the
time.  This benefits performance (provided sufficient memory and cache
devices, and possibly tweaking/tuning if necessary) ... Netapp does dedup as
a post-write operation, like a scheduled scrub.  So netapp gains neither the
performance nor storage benefit of dedup on the fly.  But the offline dedup
scales larger (lower memory requirement).

I find I benefit a LOT by knowing ZFS can be run on any generic blackbox.  I
don't need proprietary hardware or OS.  So I can "zfs send" a filesystem to
external media for archival purposes, and I can use a generic blackbox to
verify its integrity etc.  And if the DR situation arises someday, I know
I'm not dependent on proprietary stuff in order to restore.  Also, you can't
snapmirror onto tape.  It seems such a shame, to be able to efficiently and
instantly generate an incremental datastream, that is only receivable by
another licensed fully expensive proprietary chassis.  ZFS can send the
datastream wherever you want, including tape or file.  NDMP walking a
filesystem takes forever, even for incrementals, because it needs to walk
the tree and check all the files for modification.  In ZFS, you can NDMP
receive the zfs send datastream ... Or you can script the zfs send, to store
it or send it wherever you want.  It's just a data stream.  And since I have
no proprietary OS, I can install any random backup client I wish ... tar,
rsync, netbackup, backupexec, etc.  In addition to the obvious "zfs send."

And I can run all this inside a VM if I want.  In fact, something I like to
do is install ESX, then install ZFS guest, and pass-thru all the storage to
the control of the guest OS, and re-export the storage to ESX.  This
essentially layers ZFS in between ESX and the physical storage, all within
the same piece of hardware.  So I can easily snapshot and efficiently
incrementally backup guest OSes seamlessly and silently in the background.  

So ...

Clearly my perspective has biased positives in favor of ZFS, but I haven't
had any Netapp in a few years, and I don't know much else.  Can anyone shed
more positive light on either Netapp or anything else?

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