Performance concepts for integrated servers
Integrated server performance is affected by the configuration of the virtual storage and network for the integrated server.
The iSCSI-attached systems have their own memory and one or more processors, but share the IBM® i hard disk storage through virtual (simulated) disk drives (virtual storage). The disk drives are allocated to integrated servers by creating an IBM i virtual disk (network server storage space). The major difference between the integrated servers and stand-alone servers is that stand-alone servers tend to use dedicated disk drives and the integrated servers use IBM i storage spaces as virtual disks. Integrated Windows servers also include optional features to share IBM i tape, CD and DVD drives. Integrated Windows servers can use high-speed virtual Ethernet networks to communicate with other integrated servers or Power server logical partitions.
The use of IBM i storage spaces (virtual drives) provides performance benefits that are not typically available in stand-alone environments without significant storage fabric investment and maintenance costs. However, it also imposes some limitations. You should consider these limitations when planning and configuring integrated servers. The information below highlights some considerations affecting performance.
- Storage performance for integrated servers
Storage performance depends on the configuration of the integrated server environment. - Virtual Ethernet performance for integrated Windows servers
The Virtual Ethernet point-to-point connection is the default virtual network connection between the hosting IBM i partition and each integrated Windows server. The-point-to-point connection is used primarily for administrative operations which are part of the integration environment. - MTU considerations for the iSCSI network
By default, iSCSI normally uses standard 1500 byte frames. You can configure the network to use other Ethernet frame sizes to adjust network performance.
