[CentOS] mkswap, lvm and bootbits sectors
Peter Kjellström
cap at nsc.liu.se
Tue Mar 13 17:08:20 UTC 2012
On Tuesday 13 March 2012 13.41.53 Philippe Naudin wrote:
> Hello,
>
> I am confused by a warning from mkswap :
>
> When making a swap on a LVM volume, I see the following warning :
> mkswap: /dev/vg_SDB1/swap_test6_64: warning: don't erase bootbits
> sectors on whole disk. Use -f to force.
> Setting up swapspace version 1, size = 1048572 KiB
>
> Is it safe to use mkswap -f in this case ?
I'd say it's safe but why do it?
What likely happened is that the lv you ran mkswap on contained a valid
partition table (or at least boot signature). Out of paranoia mkswap left the
first block alone. So what you could gain is maybe another 512 byte in
swapspace by adding -f.
You could write a meg of zeroes to the device first and see if the mkswap
warning goes away.
/Peter
> (If that matters, the swap is intended for a virtual machine, and
> the host where I am using mkswap is a CentOS-6 server.)
>
> Thanks,
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.centos.org/pipermail/centos/attachments/20120313/7e43cb89/attachment.sig>
More information about the CentOS
mailing list