Location of logical-log files
When the database server initializes disk space, it places the logical-log files and the physical log in the root dbspace.
To improve performance by reducing the number of writes to the root dbspace and minimize contention, move the logical-log files out of the root dbspace to a dbspace on a disk that is not shared by active tables or the physical log.
To improve performance further, separate the logical-log files into two groups and store them on two separate disks (neither of which contains data). For example, if you have six logical-log files, you might locate files 1, 3, and 5 on disk 1, and files 2, 4, and 6 on disk 2. This arrangement improves performance because the same disk drive never is required to handle writes to the current logical-log file and backups at the same time.
The logical-log files contain critical information and must be mirrored for maximum data protection. If you move logical-log files to a different dbspace, plan to start mirroring on that dbspace.