Why no logical volume in fstab?

[Habib_4]

Hi guys,

I am currently doing some test builds hence all the questions in the last couple of days.
What I have found is that in '/etc/fstab' I have the following:

# See fstab(4) and sam(1M) for further details on configuring devices.
/dev/vg00/lvol3 / vxfs delaylog 0 1
/dev/vg00/lvol1 /stand hfs defaults 0 1
/dev/vg00/lvol4 /tmp vxfs delaylog 0 2
/dev/vg00/lvol5 /home vxfs delaylog 0 2
/dev/vg00/lvol6 /opt vxfs delaylog 0 2
/dev/vg00/lvol7 /usr vxfs delaylog 0 2
/dev/vg00/lvol8 /var vxfs delaylog 0 2
/dev/vg00/lvol12 /usr8 vxfs delaylog 0 2
/dev/vg00/lvol9 /opt/patrol vxfs delaylog 0 2
/dev/vg00/lvol11 /usr/openv vxfs delaylog 0 2
/dev/vg00/lvol10 /var/opt/patrol vxfs delaylog 0 2
/dev/vg01/lvol1 /bea_domains vxfs delaylog 0 2
/dev/vg01/lvol2 /beaA vxfs delaylog 0 2
/dev/vg01/lvol3 /bea vxfs delaylog 0 2
/dev/vg01/lvol4 /HP_MASTER vxfs delaylog 0 2
/dev/vg01/lvol5 /beaB vxfs delaylog 0 2
/dev/vg01/lvol6 /bea8 vxfs delaylog 0 2

As you can see from the above there is no:
/dev/vg00/lvol2.

Why not?
As in /dev/vg00 I do have an entry for 'lvol2':

brw-r----- 1 root sys 64 0x000002 Apr 12 11:29 lvol2

Please get back as this is quite tricky for me!

Cheers.

[Roberto Arias · Accepted solution]

Hello:/dev/vg00/lvol2 is the swap default. This lvol is always active and is not necesary that is in fstab file.

best regards

Roberto Arias

[Habib_4]

Thank you very much Roberto!!!

[Mridul Shrivastava]

By default, the system is configured with at least one area of device swap when
the operating system is installed (/dev/vg00/lvol2). Device swap is nothing
more than a logical volume, or a disk section, that is given to the system to
use for swap. Commands like bdf will not show swap on a system, however
swapinfo (swapinfo -tam)does. Device swap can be configured in any volume group on the system.
Using a logical volume is the most preferred when it comes to performance, and
should be configured first when the system needs additional swap. Device swap
is also divided into two different terms. The first is primary swap. This swap
device tends to be /dev/vg00/lvol2 and is created when the operating system is
installed. Primary swap can only be found on the boot drive. Any additional
device swap is called secondary swap. Secondary swap devices can be configured
in any volume group.

[sysadm_1]

Hi Habib,

/dev/vg00/lvol2 is swap by default..
This is not mounted as filesystem.
You can see the swap lvols using
"swapinfo -a" command


-sysadm-

[Habib_4]

Thanks for the advice