Improving old-fashioned UFS2 performance with lots of inodes...

[Ivan Voras]

On 29/06/2011 01:47, Jeremy Chadwick wrote:

>> unfortunately, so for now we will use UFS2, and as I said ... it seems a shame
>> that UFS2 cannot use system RAM for any good purpose...
>>
>> Or can it ?  Anyone ?
>
> Like I said: the only person (I know of) who could answer this would be
> Kirk McKusick.  I'm not well-versed in the inner workings and design of
> filesystems; Kirk would be.  I'm not sure who else "knows" UFS around
> here.

UFS will use all your memory for caching, there's no known issues here. 
Of course, you still need to read all this data in to be cached.

As Jeremy said, even ZFS will not help you with huge file systems 
without some work. You could read this: 
http://en.wikipedia.org/wiki/Sharding and simply replace "databases" 
with "file systems" and "tables" with "directories" :)