Seagate X8 Accelerator Seagate X8 Accelerator User Guide for VMware - Page 30

8.0 MULTIPLE SEAGATE X8 ACCELERATOR DEVICES Up to 24 devices are supported by the code but have tested 4 devices on a single ESXi system. For optimal performance, it is recommended that the number of X8 Accelerator devices per server not exceed the number of NUMA nodes in the system. Each device will appear as "/dev/disks/mpx.vgcN:C0:T0:L0" and can be used to create datastores. 9.0 USING X8 ACCELERATOR DEVICES IN PASS-THROUGH MODE Seagate X8 Accelerator devices can be used in pass-through mode on ESXi hosts. They can be added as a PCI device to a Linux or Windows Guest VM. In such cases, it is required that the Guest VM have the Guest OS (Windows or Linux) specific drivers installed. For using X8 Accelerator devices with Linux or Windows VMs, please consult the corresponding documentation. The system hardware and guest VM is expected to support pass-through mode. And also, guest VM should have enough memory and CPU resources as described in respective user guides. To configure X8 Accelerator in "pass through" mode, please refer VMware vSphere NOTE product documentation 10.0 OPTIMIZING PERFORMANCE Seagate X8 Accelerator devices and driver are tuned to provide good performance across a wide range of application workloads. It is, however, possible to optimize performance further by customizing your VM settings or by configuring the devices differently. 10.1 USABLE SPACE VS. WRITE PERFORMANCE By default the Seagate X8 Accelerator device creates physical partitions with a "max capacity" mode that is optimal for most real-world workloads. A small portion of the raw capacity of each X8 Accelerator device is set aside to help accelerate writes, while the majority is used to store user data. Setting the device to "max performance" mode will reduce the total usable space to achieve better write performance, especially when the device is used to near full capacity. 10.2 PARTITIONING AND WRITE PERFORMANCE The esxcli vgc config allows you to create up to two physical partitions on the Seagate X8 Accelerator device. Each of these physical partitions can have different capacity/write performance characteristics as well, so one physical partition could be optimized to have maximum space available for static user data while another can be optimized for heavily updated data (like database logs, scratch space, etc. When multiple partitions are created, the aggregate performance is divided among NOTE partitions. 10.3 SETUP RECOMMENDATIONS TO UTILIZE FULL PERFORMANCE OF X8 ACCELERATOR WITH A SINGLE GUEST VM. Create a Windows 2008 Enterprise VM with 4 LSI SCSI or PVSCSI controllers Configure X8 Accelerator device in "maxperformance" mode. Create a VMFS5 datastore using the available space. Add 4 Virtual Disks to the VM: attach each vmdk to each of the 4 SCSI controllers. From within the windows VM, create a striped volume with the 4 Virtual Disks. Assign a drive letter and use this volume for max performance The above configuration is for demonstration purposes only. Guest VMs use LSI SCSI adapters by default, however, there are instances where PVSCSI adapters are recommended for certain workload scenarios for better CPU utilization. Comparison and explanation between LSI SCSI and PVSCSI adapters are beyond the scope of this document, and Seagate recommends consulting VMware product documentation or support for choosing between the two. SEAGATE X8 ACCELERATOR FOR VMWARE ESXI USER GUIDE, REV. A 26