vSphere 6.5 Storage

VMware
This technical white paper describes the various features of the new vSphere 6.5 Core Storage in detail Storage Limit Improvements Pluggable Storage Architecture (PSA) Improvements VMFS-6 UNMAP Storage I/O Control vSphere VM Encryption New Virtual Storage Hardware NFS ISCSI Improvements
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VMware vSphere 6 Metro Storage Cluster Recommended Practices

VMware
VMware vSphere® Metro Storage Cluster (vMSC) is a specific configuration within the VMware Hardware Compatibility List (HCL). These configurations are commonly referred to as stretched storage clusters or metro storage clusters and are implemented in environments where disaster and downtime avoidance is a key requirement.   This best practices document was developed to provide additional insight and information for operation of a vMSC infrastructure in conjunction with VMware vSphere. This paper explains how vSphere handles specific failure scenarios, and it discusses various design considerations and operational procedures. For detailed information about storage implementations, refer to documentation provided by the appropriate VMware storage partner.  
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Windows Server Technical Preview – Storage Replica

Microsoft
Storage Replica enables storage-agnostic, block-level, synchronous replication between clusters or servers for disaster recovery, as well as stretching of a failover cluster for high availability. Synchronous replication enables mirroring of data in physical sites with crash-consistent volumes ensuring zero data loss at the file system level. Asynchronous replication allows site extension beyond metropolitan ranges with the possibility of data loss. To help you get familiar with Storage Replica, we have a downloadable guide to provide you with step-by-step instructions for evaluating the Stretch Cluster and the Server-to-Server scenarios. These are both designed for Disaster Recovery and provide “over the river” synchronous metro replication.
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SCSI Bus Sharing on SCSI Cards

VMware
Recently working with a monster VM I had a request to add more capacity after looking at the properties of this machine I noticed that it had almost reach the maximum number of possible hard drives (SCSI devices) that could be allocated due to the amount of capacity and RDM's required.  So based on this I thought I would write a blog post on why there is this limitation. Now lets just take a quick look at the wide SCSI bus which is capable of serving SCSI ID 0 to 15 which means 16 SCSI targets. As you know (if you've dealt with SCSI) traditionally SCSI ID 7 is reserved for the SCSI card itself which then leaves us with 15 SCSI disk targets and with the maximum number of 4 SCSI adapters allowed in…
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VMware Virtual SAN Sizing Tool

VMware
All Virtual SAN customers and enthusiasts can easy get sizing ideas and estimations on the amount hardware resources necessary to support a particular Virtual SAN design. All you will need  to do is provide a few virtual machine inputs based on capacity, performance, and availability requirements. The purpose of this tool is to help determine the hardware specifications for hosts in a Virtual SAN cluster required to run a set of virtual machines defined by a set of input characteristics. These important assumptions should be understood before using this tool: All hosts in the cluster are assumed to have an identical hardware profile, i.e. numbers of hard drives and flash devices, amount of physical RAM, and number of CPU cores. All virtual machines are assumed to be identical in storage…
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Symantec NetBackup and PureDisk appliances

Hardware
This may be off topic but I thought I would cover it anyway as a colleague of mine found the information very useful.  We had a faulty 1TB disk (in slot 16) which needed replacing but looking at the front of the appliance there was no indication/labels to give us a clue as to location of  slot 16.  We trawled the internet for hours and finally came up with the following diagrams that perhaps one day may help you out and save you many hours of surfing. Following tables show the location of hotspare disks and data disks in different models of Symantec NetBackup and PureDisk Appliances as seen through the front panel: 5000, 5020 and 5200 appliances: 5220 appliances: Note: 2 disks containing the Operating System are in-built and not shown…
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MetaLUNs Explained

Hardware, Storage
The purpose of a MetaLUN is that a Clariion can grow the size of a LUN on the ‘fly’. Let’s say that a host is running out of space on a LUN. From Navisphere, we can “Expand” a LUN by adding more LUNs to the LUN that the host has access to. To the host, we are not adding more LUNs. All the host is going to see is that the LUN has grown in size. We will explain later how to make space available to the host. (more…)
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VMware VMFS: Technical Overview and Best Practices

VMware
The VMware Virtual Machine File System (VMFS) is a high performance cluster file system that allows virtualization to scale beyond the boundaries of a single system. This paper gives a technology overview of VMFS, including a discussion of features and their benefits. The paper highlights how VMFS capabilities enable greater scalability and decreased management overhead. It also provides best practices and architectural considerations for deployment of VMFS. Download http://www.vmware.com/files/pdf/vmfs-best-practices-wp.pdf Source: VMware
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Storage performance – IOPS & Latency

Storage
Storage I/O bottlenecks can have a big impact on virtual environments and can wreak havoc on the performance of the virtual machines within them. The guest operating systems and applications running inside VMs are constantly reading and writing to and from their virtual disks and anything that delays this can slow a VM to a crawl. Of all the resources a host manages, traditional storage devices are typically the slowest resource because they rely on mechanical spinning hard disks. In addition shared storage arrays are commonly used in virtual environments because of the many features that require shared storage and as a result there is a longer path to get to storage resources. Storage I/O must leave the host through an I/O adapter and traverse a storage or traditional network…
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What is RAID?

Hardware
I've had a number of emails asking me to provide details about RAID well here goes I think I've covered everything. RAID is a group of independent physical disks that provides high performance by increasing the number of drives used for saving and accessing data. A RAID disk subsystem improves I/O performance and data availability. The physical disk group appears to the host system either as a single storage unit or multiple logical units. Data throughput improves because several disks are accessed simultaneously. RAID systems also improve data storage availability and fault tolerance. Data loss caused by a physical disk failure can be recovered by rebuilding missing data from the remaining physical disks containing data or parity. RAID is not a backup solution. It does not replace a good data backup…
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