Moving the database from a filesystem to another

Hi All,
one of my customers has a Postgres 7.2.3 DB on an RH7.1 box. Running df it
seems that the DB is not on the appropriate filesystem.

/dev/md1               5040352   2562316   2221992  54% /
/dev/md0                100020      8989     85867  10% /boot
/dev/md2              28831612      9800  27357244   1% /data

I suppose md2 was planned for storing the database, but it is on md1
($PGDATA = /var/lib/pgsql/data). Am I right?

md1 is about fulling up in some months, so I think it should be a good idea
to move the store to md2. How can I do this?
Is it enough to copy/move the directory /var/lib/pgsql/data to eg.
/data/pgsql/data and set $PGDATA to that directory?

Thank you,
-- Együd Csaba