[BUGS] mountmsdosfs(): disk too big, sorry

[Trevor Roydhouse]

Trevor Roydhouse wrote:
> Jerahmy Pocott wrote:
> 
>> Any ideas?
> 
> The source code (msdosfs_vfsops.c) suggests:
> 
>                          error = EINVAL;
>                          vfs_mount_error(mp,
>                             "Disk too big, try '-o large' mount option");
>                          goto error_exit;
> 
> (I'm running FreeBSD 7.0-STABLE amd64, so this option might not be 
> available to you. It's not documented in the man page for mount_msdosfs 
> btw.)

I should have read further whereupon there is a significant caveat:

         /*
          * Experimental support for large MS-DOS filesystems.
          * WARNING: This uses at least 32 bytes of kernel memory (which 
is not
          * reclaimed until the FS is unmounted) for each file on disk 
to map
          * between the 32-bit inode numbers used by VFS and the 64-bit
          * pseudo-inode numbers used internally by msdosfs. This is only
          * safe to use in certain controlled situations (e.g. read-only FS
          * with less than 1 million files).
          * Since the mappings do not persist across unmounts (or 
reboots), these
          * filesystems are not suitable for exporting through NFS, or 
any other
          * application that requires fixed inode numbers.
          */
         vfs_flagopt(mp->mnt_optnew, "large", &pmp->pm_flags,
           MSDOSFS_LARGEFS);

-- 
Trevor Roydhouse                            Mob  : 0415-448-273
BJuris, LLB, LLM (UNSW)
System Developer
Australasian Legal Information Institute    Web  : www.austlii.edu.au