sorting on a field and then making it uniq

[Donald C Nelson]

I have a file as follows:
/dev/rdsk/c8t0d4 :EMC :SYMMETRIX 40031000
/dev/rdsk/c9t8d4 :EMC :SYMMETRIX 40031000

These are mirrored disks. How can I sort on the field to only abstract the primary disk and not the mirrored disks.

[Bill Hassell]

In LVM, the primary and secondary relationship is arbitrary and can be reversed at any time. And because the two line are not the same (the device file is different), you would have to write a script to see if the ID is the same and then skip if true.

[James R. Ferguson · Accepted solution]

Hi Donald:

If you want the sort based on the fourth space-delimited field, then:

sort -k4 -u

Regards!

...JRF...

[Donald C Nelson]

Thanks James, before you sent me the response I had already type that command.