Installation guide

Sorting LVM Reports
57
4.8.3. Sorting LVM Reports
Normally the entire output of the lvs, vgs, or pvs command has to be generated and stored internally
before it can be sorted and columns aligned correctly. You can specify the --unbuffered argument
to display unsorted output as soon as it is generated.
To specify an alternative ordered list of columns to sort on, use the -O argument of any of the reporting
commands. It is not necessary to include these fields within the output itself.
The following example shows the output of the pvs command that displays the physical volume name,
size, and free space.
# pvs -o pv_name,pv_size,pv_free
PV PSize PFree
/dev/sdb1 17.14G 17.14G
/dev/sdc1 17.14G 17.09G
/dev/sdd1 17.14G 17.14G
The following example shows the same output, sorted by the free space field.
# pvs -o pv_name,pv_size,pv_free -O pv_free
PV PSize PFree
/dev/sdc1 17.14G 17.09G
/dev/sdd1 17.14G 17.14G
/dev/sdb1 17.14G 17.14G
The following example shows that you do not need to display the field on which you are sorting.
# pvs -o pv_name,pv_size -O pv_free
PV PSize
/dev/sdc1 17.14G
/dev/sdd1 17.14G
/dev/sdb1 17.14G
To display a reverse sort, precede a field you specify after the -O argument with the - character.
# pvs -o pv_name,pv_size,pv_free -O -pv_free
PV PSize PFree
/dev/sdd1 17.14G 17.14G
/dev/sdb1 17.14G 17.14G
/dev/sdc1 17.14G 17.09G
4.8.4. Specifying Units
To specify the unit for the LVM report display, use the --units argument of the report command. You
can specify (b)ytes, (k)ilobytes, (m)egabytes, (g)igabytes, (t)erabytes, (e)xabytes, (p)etabytes, and
(h)uman-readable. The default display is human-readable. You can override the default by setting the
units parameter in the global section of the lvm.conf file.
The following example specifies the output of the pvs command in megabytes rather than the default
gigabytes.