problem in remounting the logical volume in 2.6.7 kernel

The original message was received at Wed, 11 Aug 2004 17:58:22 +0530 from [10.44.50.16]

----- The following addresses had permanent fatal errors -----
<linux-lvm@redhat>
(reason: 550 Host unknown)

----- Transcript of session follows -----
550 5.1.2 <linux-lvm@redhat>... Host unknown (Name server: redhat: host not found)

hi ,
i am facing a problem while mounting a logical volume. I am able to
create volume group and logical volumes (LVM2) in linux 2.6.7 of type ext3 and making entry in /etc/fstab and executed command mount -a. mount is successfully working. but after rebooting the machine, it is giving error
unable to mount may be the device is a swap device ....bla bla..

i tried to mount it manually but it is not mounting again and it is
giving error /dev/volume-group1/lvm1" is not a valid block device.

what is the problem and how to come out from it???

please reply me..

regards
sridhar.