[RFC,PATCH 0/4] Dynamic Pseudo Root

[J. Bruce Fields]

On Fri, Dec 07, 2007 at 04:49:06PM -0600, Tom Haynes wrote:
> Steve Dickson wrote:
>>
>> A concern I have with this implement, is how scalable it is? Do server 
>> export hundreds or even thousands of directories? I don't know...  If they 
>> do, then creating a mount point for each export probably will not scale 
>> very well.   
>
> When Linux pulls in zfs (if ever), then this will be a reality. Look at 
> http://developers.sun.com/solaris/articles/nfs_zfs.html:

Thanks for the pointer!  That's a more detailed discussion of the
problem than I'd seen before.

--b.

>> Until Solaris ZFS was installed on the file server, it had about 12 
>> exports. One week before the home directories were migrated totally to 
>> ZFS, the server had about 300 exports. Right after the migration, it had 
>> about 1300 exports. The server currently has about 1500 exports.
>>
>> And the Sun NFS team started seeing a serious impact on the loading of 
>> shares at boot time. As previously mentioned, a design originally made to 
>> handle 10 exports -- even one that was redesigned 10 years ago -- does not 
>> scale well when going to 1500 exports. And Sun has customers that report 
>> going to 15,000 exports.
>>
>
> And those are numbers that NetApp's Data ONTAP was able to handle 2 years 
> ago.
>
> E.g., you should expect those types of exports to happen sooner than later 
> in Linux...