[PVFS-developers] faked /etc/mtab entry

[Robert Ross]

James,

I've just about gotten the df output working right (it's the statfs() call
that has to work).  It will report the total size, the amount used, and an
estimate of the amount available (min_free * nr_iods).

It's nice to see that the mtab entry is about all that is holding us back
on the "real mounting" (i.e. having an entry in /etc/fstab, using plain
ole mount) front; perhaps we can get that wrapped up soon too.

I will try to get a couple of other little things done and do a code drop
this coming week (Oct. 22-27).  It would be good for me to get this stuff
out before I start mangling things for the new metadata code.

We'll probably never use UDP, so I wouldn't sweat that :).  It's a good
point though, and I hadn't noticed that before.

Rob

On Sun, 22 Oct 2000, James MacKinnon wrote:

> 
> After having successfully installed PVFS on a 48 node SMP Intel cluster
> (using the module and friends for mount.pvfs), I toyed with manually
> faking a mount point entry in /etc/mtab:
> 
> 	PVFS /pvfs pvfs rw 0 0
> 
> (this is similar to an AFS style entry)
> 
> This allows for /pvfs showing up in a df listing:
> 
> [root@thor-gw jmack]# df /pvfs
> Filesystem           1k-blocks      Used Available Use% Mounted on
> PVFS                 134217728       128    131072   0% /pvfs
> 
> However, the numbers are completely bogus (I have about 311 GB total on
> PVFS distributed across the nodes).
> 
> Does anyone more familiar with the code have any ideas on how to
> implement this so the numbers either mean something useful, or
> if this turns out to be a tricky thing to do, perhaps to do it
> the way AFS does it:
> 
> [root@thor-gw jmack]# df /afs
> Filesystem           1k-blocks      Used Available Use% Mounted on
> AFS                    9000000         0   9000000   0% /afs
> 
> and merely provide summary total info (I've never seen thes AFS numbers
> change, and so they are perhaps just as bogus).
> 
> On a totally different topic:
> 
> Speaking of AFS, PVFS IOD currently uses port number 7000 as the default.
> If you ever get PVFS fully migrated to UDP, this will conflict with the 
> AFS protocol (which uses UDP 7000 to 7010).