How do I determine the file logical order of the Lustre extents, given the device logical order?  Can I assume the file logical order of the extents will follow the
the device order indicated by obdidx from the "lfs getstripe" output?

 Is it safe to assume that the order of the devices as discovered in the filefrag output is always the same as the order of the devices in the "lfs getstripe" output?  In the output below, both have the order 4, 12, 9, 1.  Is this coincidental or is it a given?

% lfs getstripe -v /lus/scratch/p01940/pwrite.dat
/lus/scratch/p01940/pwrite.dat
lmm_magic:          0x0BD10BD0
lmm_seq:            0x2002dab80
lmm_object_id:      0xd1e
lmm_stripe_count:   4
lmm_stripe_size:    4194304
lmm_stripe_pattern: 1
lmm_layout_gen:     0
lmm_stripe_offset:  4
        obdidx           objid           objid           group
             4          845042        0xce4f2                0
            12          845220        0xce5a4                0
             9          844466        0xce2b2                0
             1          844523        0xce2eb                0

% /usr/sbin/filefrag -v
/lus/scratch/p01940/pwrite.dat
Filesystem type is: bd00bd0
File size of /lus/scratch/p01940/pwrite.dat is 4194304000 (4096000 blocks of 1024 bytes)
 ext:     device_logical:        physical_offset: length:  dev: flags:
   0:        0..   10239: 1850072064..1850082303:  10240: 0004: network
.
 115:   928768.. 1023999: 1851001856..1851097087:  95232: 0004: network
 116:        0..   16383: 14315287552..14315303935:  16384: 000c: network
.
 270:  1021952.. 1023999: 14316310528..14316312575:   2048: 000c: network
 271:        0..   10239: 4657097728..4657107967:  10240: 0009: network
.
 381:   945152..  946175: 4658040832..4658041855:   1024: 0009: network
 431:   978944.. 1023999: 4333852672..4333897727:  45056: 0001: network
/lus/scratch/p01940/pwrite.dat: 421 extents found
%