ZFS (was Reliable Firewire drives)

[Dan Shoop]

On Jan 13, 2008, at 4:08 PM, Brett Dikeman wrote:

> On Jan 12, 2008 2:32 AM, Lewis Butler <kremels at kreme.com> wrote:
>
>>> Running ZFS on any sort of production environment on anything except
>>> 64 bit Sun hardware w/Solaris means running on borrowed time, at
>>> least for the moment.
>>
>> I don't think that's quite true.
>
> http://www.google.com/search?q=zfs+crash
> http://www.google.com/search?q=zfs+corrupt
>
> ZFS is not in STABLE in FreeBSD and there are numerous reports of it
> crashing.  The documentation for the ZFS FUSE module clearly states
> "do not use this for anything important."  The MacPorts ZFS driver
> contains an errata list that demonstrates it has very basic problems
> with both the implementation of the filesystem and the operating
> system's support for ZFS-isms.  Apple only provides read support in
> the release of Leopard.
>

OK if you're talking about the FUSE port of ZFS well this is not ZFS,  
it's a US filesystem version of it, that is it's not the real ZFS.  
Since FUSE itself has significant issues obviously anything based on  
it will too.

However there is a real port of ZFS which exists. For the Mac as well.

>  I don't know how much clearer I can make it to you that ZFS is not a
> stable filesystem.  It is not considered ready for production on
> anything except 64-bit Solaris, and even on that platform, it has
> issues.  For example, even on Solaris 10 8/07, it can't be used as a
> root filesystem.

ZFS, as implemented by Sun, or the Apple build for OS X, has proven to  
be far more stable than many currently shipping filesystems for the  
same platforms. Is it 100% stable, no, but nothing is. That said ZFS  
will tell you a boatload more about what's going wrong before hand.  
We've had several cases where ZFS has alerted us to issues, and in  
many cases fixed them (including things not fixable at all in other  
FS), ebfore they've developed into problems. We've found disks not up  
to production muster by just writing to them once. I can't speak well  
enough about ZFS both on Solaris and Mac OS X.

As for why it's not considered production worthy on 32 bit Solaris,  
this is an issue with 32 bit Solaris, not ZFS.

And yes, very very unfortunately, ZFS can't be used, currently, as a  
boot volume for Solaris (or OS X) but this in NO WAY represents  
problems with its stability but issues regarding boot loaders. There  
aren't any boot loaders that currently support ZFS filesystems.

-dhan

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Dan Shoop
Computer Scientist
iWiring / U.S. Technical Services

shoop at iwiring.net
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