Hi Hertha, How to find out minor device of a major device (for entry in rawdevices file)

[sunhux G]

Hi Hertha,


Thanks.
Noticed that in the rawdevices file, there's column for minor device
file name.

I heard for each of the /dev/mpath/mpathx, there's actually
two corresponding
minor devices (/dev/sd...).

Yes, 2 /dev/sdx  devices are the actual physical path to the SAN while
/dev/mpath/mpathx is the logical path with redundancy (ie if one physical
path is down, it will use the other path).

How do I find out the physical paths for a logical path?


Tks
U


==================================

You don't convert it back, you simply use it as a raw device, but know
that part of the raw device will be corrupt as you have overwitten
certain blocks with the filesystem's superblocks.

To use a partition as a raw device,
- add it to /etc/sysconfig/rawdevices e.g., by adding the line

   /dev/raw/raw1 /dev/mapper/mpath0

- and restart the rawdevices service:

  service rawdevices restart

Kind regards,

Herta