Extensive database transaction workloads may require adequate
memory resources for database buffer pools. Larger database buffer
pools allow for higher transaction rates, because less disk I/O
must be done. The maximum usable amount of memory for a 31-bit
Linux system is 2GB. This limit is withdrawn, when using a 64-bit
Linux system. So for larger Linux systems more shared memory can be
assigned for the database buffer pools, provided that the database
product has native 64-bit support.
Test environment
IBM eServer zSeries 900 (2064-216)
IBM TotalStorage Enterprise Storage Server 2105-800
LPAR with 12 CPUs, 2-20GB memory
Novell/SUSE SLES 8 + SP3 for IBM zSeries (64-bit),
updated kernel 2.4.21-228
IBM DB2 Universal Database ESE v8.2 (64-bit)
Benchmark DB2 OLTP
Database data Logical Volume (LV): 8 CHPIDs, 8 host
adapters, 25 x 10GB FCP/SCSI disks in 8 ranks, ext2
filesystem
