Here’s a link to the full PDF details: I captured some screen shots that step though the P420i setup. This process accelerates reads for all RAID levels and writes for RAID 0” Involving firmware layers, and instead use an accelerated I/O operation called HP SSD Smart Path (seen in figure 1). HP SSD Smart Path technology allows I/O requests that meet certain requirements to bypass the normal I/O path “HP SSD Smart Path improves the performance of select HP Smart Array Controllers in SSD-based HP ProLiant Gen8 servers. Here’s the description from the HP “Optimized solid-state drive performance with HP SSD Smart Path” Technical white paper: Recommend enabling it to accelerate reads and writes. Finally, there’s an option to enable HP SSD Smart Path and we So, you can deselect all of the disks that will be used for VSAN, thus disabling Read cache for them. When the array configuration is saved from ACU, the information is stored on the RAID information sector (RIS) on each hard drive. 13.2.2.1 LOCATION OF ARRAY CONFIGURATION DATA. Some operating systems support fewer than 32 logical drives. I recently discovered that you can also selectively pick and choose which disks to enable cache for. Up to 32 logical drives can be defined with any HP Smart Array controller. Recommends setting it to 100% Read which essentially disables Write cache. In the case of the HP P420i, you cannot disable the I/O Controller cache so VSAN Also, when destaging write cache, we want to ensure that the writes are committed to disk and not in I/O Controller cache. Since VSAN handles Read and Write caching at the software layer, there’s no need to do it at the hardware level. In general, VSAN recommends disabling Read and Write cache for any I/O Controller. To resolve, follow these directions to implement the correct driver: OK, a little background/overview on I/O Controller guidance for VSAN. The bug reduces the queue depth to 26, instead of 1024, causing poor performance in VSAN. Bear in mind, I am not an HP server hardware expert, so your comments are greatly appreciated.īefore I go too far, there is a bug in the HP async controller driver for the HP 420i that is included in the HP ESXi image.
There are things I’ve discovered that might not be obvious but can help in the VSAN setup. The Smart Array controller powers up using a default configuration that lets it function efficiently until the retrieval of device-unique IDs and associated loss factor data.
Others are looking for guidance from VMware on how to configure for VSAN. We also test Smart Array controllers with all compatible operating systems, HP servers, server backplanes, and compatible HP devic. Many are very familiar with HP hardware and just know how to set things up.
I’ve been working with many customers over the last several months and found that