128 Planning, Installing, and Managing the IBM System x3950 M23.3.3 ServeRAID-MR10k RAID controllerTo extend the basic RAID-0 (IS) and RAID-1 (IM) provided by the internalLSI1078 SAS controller and support the external SAS port, install the optionalServeRAID-MR10k controller. The ServeRAID-MR10k controller is a PCIe x8RAID controller implemented as a DIMM card with 240 pins and has 256 MBECC DDR2 cache.The ServeRAID-MR10k is installed into a dedicated socket on the I/O board nearthe PCI Express slots as shown in Figure 3-21.Figure 3-21 Optional installed ServeRAID-MR10kThe ServeRAID-MR10k supports stripe sizes from 8 KB to 1024 KB. The defaultstripe size is 128 KB. The SAS drive can be driven with up to 3 GBps for eachport in full-duplex mode.The controller supports up to 64 virtual disks, and up to 64 TB logical unitnumbers (LUNs). It supports up to 120 devices on the external x4 port. IBMsupports the use of up to nine cascaded and fully populated EXP3000enclosures on the external port with up to a total of 108 disk drives.The ServeRAID-MR10k controller has an LSI 1078 ASIC on the designatedDIMM card. The cache data is secured by the iTBBU package as described in“Intelligent transportable battery backup unit (iTBBU)” on page 130.
