Logical volume of 0 size

[SSP_1]

Hi Guys,

Wanted to know how to create a logical volume of zero bytes of size.

lvcreate -L 0 /dev/vg01 - this don'e work.

Pl suggest

[Martin Johnson]

Leave off the "L" parameter.

HTH
Marty

[Pete Randall · Accepted solution]

From man lvcreate:

"If you omit the -l and -L options, the logical volume is created with
zero length. This permits you to choose its physical volume location
when you allocate logical extents with the lvextend command (see
lvextend(1M)). If you specify -l or -L, the location is determined
automatically."


Pete

[James R. Ferguson]

Hi:

You must *omit* the size option ('-L') to create a zero size logical volume.

See the 'lvcreate' man pages.

Regards!

...JRF...

[A. Clay Stephenson]

Read the man pages more carefully and you will note that if you omit -L (and -l) options an LVOL of 0 length will be created. Typically this is done to enable extent-based striping using subsequent lvextend commands.

If you are doing this for performance reasons, don't expect huge improvents. The problem is that even the smallest possible PE (1MB) is still a big strip size -- which should really be in the 64KB range to distribute the I/O quickly in a round-robin fashion.

[Steven E. Protter]

I'm confused.

Right after you run the lvcreate command, you have a logical volume with size zero.

Then you need lvextend to give it size.

Example.

lvcreate -C n -n schmo /dev/vg01

Created a noncontiguous logical volume called schmo

lvextend -L 100 /dev/vg01/schmo /dev/dsk/c1t1d0

Now its got 100 Megabyes of space.

What did I miss?

SEP

[Caesar_3]

Hello!

When you create lv without parameter of the size the size will be zero as you want.

Caesar