20TB Storage System (fsck????)

[Petri Helenius]

Max Clark wrote:

>Ohh, that's an interesting snag. I was under the impression that 5.x w/ PAE
>could address more than 4GB of Ram.
>  
>
It does. However as long as a pointer is 32 bits, your address space for 
a process
is maxed out at 4G which translates to about 2.5G user after kernel and 
other
things have taken their toll.

>If fsck requires 700K for each 1GB of Disk, we are talking about 7GB of Ram
>for 10TB of disk. Is this correct? Will PAE not function correctly to give
>me 8GB of Ram? To check 10TB of disk?
>
PAE functions correctly but does not provide for 7G address space.

>Is there anyway to bypass this requirement and split fsck into smaller
>chunks? Being able to fsck my disk is kinda important.
>  
>
Yes, you do that by splitting up the filesystem to smaller filesystems. 
Kind of obvious?

>I have zero experience with either itanium or opteron. What is the current
>status of support for these processors in FreeBSD? What would the preferred
>CPU be? Will there be PCI cards that I would not be able to use in either of
>these systems?
>  
>
I´m personally biased towards the Opteron, but that´s more based on that 
it makes
more sense than their technical merits so far (because neither has too 
much).

Both CPU´s should work fine with 5.2 according to the TODO list. 
Meanwhile I suggest
you play with the number of inodes on the 10TB filesystem and see how 
that affects
the memory usage.

Pete