Hyper Converged Infrastructure ( #HCI ) is starting to disrupt traditional storage markets (SAN, NAS + DAS) as enterprise IT begins to replicate. #Hyperscale public cloud provider’s infrastructure. Public cloud giants such as #AWS and #Microsoft #Azure have developed their own scale-out, software-defined enterprise storage built on commodity servers and disks. Adding the enterprise features from existing SAN and NAS devices into software allows the use of commodity hardware while shifting the storage directly to the host to improve performance and scalability. The storage is provided directly by the host. The storage is scaled-out, as are the compute resources, providing a truly scalable and cost-effective solution. A report from 2016 shows the predicted change from traditional storage to HCI and Hyperscale technologies for the next 10 years.
Even though different vendors provide HCI solutions, but I am not here to compare features between them. VMware’s HCI offering is VMware vSphere combined with their Software Defined Storage (SDS) solution — VMware vSAN. I will cover vSAN and Veeam’s recent announcement to provide further support.
VMware vSAN: What is it and what challenges does it overcome?
With traditional storage, customers faced several challenges such as the hardware was not commodity and it often created storage silos that lacked granular control. Deploying traditional storage could be time consuming because it often included multiple teams and lacked automation.
By moving the storage into software, vSAN provides a linear scalable solution using the same management and monitoring tools VMware admins are already using, while also providing a modern, policy-based and automated solution.
What does the VMware vSAN architecture look like?
vSAN is an object-based file system where VMs and snapshots are broken down into objects and each object has multiple components. vSAN objects are:
VM Home Namespace (VMX, NVRAM)VM Swap (Virtual Memory Swap)Virtual Disk (VMDK)Snapshot Delta DiskSnapshot Memory Delta
Other objects can exist such as vSAN performance service database or VMDKs that belong to iSCSI targets. An object can be made up of one or more components, depending on different factors such as the size of the object and the storage policy assigned to the object. A storage policy defines such factors as Failure to Tolerate and stripe size. For an object to have a failure tolerance of RAID 1 would mean two full copies of the data is distributed across two hosts with a third witness component on a third host, resulting in tolerance for a full host failure. Rack awareness and multiple-site fault domains can also be configured, which can dictate how the objects are distributed.
vSAN uses the concept of disk groups to pool together flash devices and magnetic disks as single management constructs. A disk group is comprised of one flash device for the read cache/write buffer and up to seven capacity devices that can be magnetic disks (Hybrid mode) or flash (All-Flash mode). A disk group must have a cache tier with a capacity tier, and a host can have up to five total disk groups.
Any supported hardware can be used for vSAN. VMware has extensive HCL available, but it also provides vSAN-ready nodes with a multitude of server hardware vendors that come pre-built with all supported hardware.
Other HCI providers require a virtual appliance to run on the host for offloading to the storage. This typically requires reserved CPU and memory from each host in the cluster. vSAN is directly embedded into the vSphere hypervisor kernel by deployment of the vSphere Installation Bundle (VIB). vSAN does still require resources, typically up to 10% of the hosts compute, but this doesn’t compete with other VMs for resources. Because it is integrated with vSphere, the admin uses the same tools to manage that are used for vSphere, and vSAN has full support for native vMotion and DRS.
Standard and 2-Node Cluster deployment methods are supported with vSAN Standard licenses, with Stretched Cluster deployment enabled through the vSAN Enterprise license. Because the vSAN is all in the software, these deployments can be scaled as required.
https://www.veeam.com/blog/deep-dive-on-vmware-vsan-6-6.html
No comments:
Post a Comment