Nutanix and SAS - https://www.nutanix.com
SAS 9.4 has been tested on Nutanix NX Models – both as a hyper-converged infrastructure (HCI), as well as using Nutanix as back-end storage only, for external hosts. The Nutanix HCI functioned well in both modes of usage. Customers are successfully running SAS on Nutanix AHV today, they ensured success by working with SAS and Nutanix to confirm their Nutanix cluster could perform well with their SAS workload. HCI platforms are challenged to provide high performance IO across the scale-out cluster so understanding your SAS IO requirements is important.
Please note if you are looking to run a very large heavy sequential IO workload, the Nutanix may not be the best storage for your SAS application.
SAS workloads require high IO bandwidth, a minimum of 125 Megabytes per second. Nutanix stores file system data redundantly across storage internal to each HCI node. This can place a heavy load on the network interface cards (NICs) that connect the HCI nodes. Based on our experience, we highly recommend the following:
- SAS WORK file systems fare better on hyperconverged, scale-out IO subsystems, when they are contained to the local node processing on them (such as EXT4 or XFS). Please remember that the 50/50 READ/WRITE mix, with high data amplification produced by SAS tasks in SAS WORK, will heavily stress the cluster interconnects and bandwidth.
- Pursuant to the above, a minimum of a 25 Gbit network interconnectivity is required for the Nutanix cluster. For best performance it is a good idea to use 40 Gbit or faster network infrastructure.
- Nutanix offers several types of storage devices. SAS and Nutanix highly recommend NOT using HDD for SAS storage on Nutanix nodes. Given the challenges of interconnect latency on scale-out HCI, the back-end devices need to be highly performant to handle block redundancy over the already heavy READ/WRITE block activity. We recommend using WRITE-Intensive, high performance SSD and/or NVMe devices. Please work with your Nutanix engineer to find the best fit/cost for your application.
- CPU/Memory Sizing. When determining the size of the Nutanix nodes, please note that the number of cores and memory needed for the SAS applications, are in addition to the number of cores and memory required by the Nutanix Controller VM.
- Nutanix Cluster Sizes. When planning on deploying a large SAS System to a scale-out cluster like Nutanix, it is especially important to determine capacity and growth for not only the SAS application, but also back-end data services. Backups, DR, HA, failover, encryption, de-duplication, compression, and redundancy all need to be managed by Nutanix. This means the node-level resources will be impacted and must be sized accordingly. Please work with your Nutanix engineer to determine what back-end service requirements you have, and how they can be implemented and sized on various Nutanix systems.
- Nutanix recommends using Acropolis Hypervisor (AHV) with natively attached volume groups for the SAS file systems.
