bind log file too big

[G H]

hello all,

i have CSW9.9.5,REV=2014.05.08 on old S10 sparc.
After 2 days, named.run is more than 2.5Gb, even i did:
/opt/csw/sbin/rndc notrace

Is it normal? Is it preferable to use logadm to rotate this file or a 
custom script?

thanks in advance for help,

gerard