[OpenAFS] zfs File system

Jason Edgecombe jason@rampaginggeek.com
Mon, 21 Apr 2008 18:00:29 -0400

Jason Edgecombe wrote:
> Russ Allbery wrote:
>> Robert Banz <rob@nofocus.org> writes:
>>> On Apr 21, 2008, at 1:10 PM, Russ Allbery wrote:
>>>> I think it's generally a good idea to stick with one server
>>>> implementation on all platforms since that way everyone runs the same
>>>> (tested) code, but I seem to recall the migration from inode to namei
>>>> is pretty heinous (as in you probably can't do it in place and need to
>>>> bring up another server and move everything).
>>> Nothing wrong with leaving the code in there, just don't make it the
>>> default.
>> The problem with changing the default is that I'm worried really bad
>> things then happen if you blindly update your Solaris file server from
>> before the default change to after the default change.
>> Maybe we could fix that so that it would safely error out.  (Maybe it
>> already does, actually; I've not checked.)
> It does error out. A namei fileserver will refuse to start and log an 
> error message if a vice partition used to be inode. This happens even 
> if you run "rm -fr *". I had to run mkfs/newfs on my vice partitions 
> in order to switch formats -- after moving the data off, of course.
> on a good note, namei seems to be faster than inode node for vos 
> operations. The speed-up with ufs logging vs. nologging is worth 
> switching to namei.
BTW, in Solaris 9 9/05HW an later, ufs logging is on by default and must 
be disabled in the vfstab. This is different from previous behavior 
which would only turn on logging if the filesystem exceed a certain size.

We've decided to use namei for all new fileservers because of the 
performance boost. It is more noticeable on stuff like fibre channel arrays.

I'll stop replying to myself now... ;)