DB2 Database for Linux, UNIX, and Windows

You might consider using a RAID level 1 hardware disk array or
a software disk array for your logs, because this provides recoverability
to the point of failure, and offers good write performance, which is important
for logs. To do this, use the mirrorlogpath configuration parameter
to specify a mirror log path on a RAID level 1 file system. In cases where
reliability is critical (because time cannot be lost recovering data following
a disk failure), and write performance is not so critical, consider using
a RAID level 5 hardware disk array. Alternatively, if write performance is
critical, and the cost of additional disk space is not significant, consider
a RAID level 1 hardware disk array for your data, as well as for your logs.