lpar01> mount /emre
mount: 0506-324 Cannot mount /dev/emre_lv on /emre: There is a request to a device or address that does not exist.

Firstly you have to look vg.

lpar01> lspv
hdisk0          00f62a6c98758859                    rootvg          active
hdisk1          00f62a6ca2279d3e                    swap            active
hdisk2          00f62a6cdf8874f5                    emrevg
hdisk3          00f62a6cdf8875ff                    emrevg

Then

lpar01> varyonvg emre_vg
lpar01> mount /emre