Computer Storage

In the field of data storage (computer storage), RAID is a key term. This is a technology for storing data over several disks. There are a number of different methods (schemes), but in most cases reliability and speed increase. In general, we can say that RAID combines several disks into one logical unit. Data is usually split and stored (and read) on several disks at once, thus increasing write/read speed. Furthermore, a checksum is stored on the next disk, so that data can be restored even if a certain part (disk) fails.

Computer storage is an area that deals with the storage of data in a computer environment. From locally connected devices to remote storage network solutions. A storage device can be a hard disk, disk array, tape or optical drive for backup, etc. The article only briefly describes the basic storage connection architectures (DAS, NAS and SAN), mentions protocols (FCP, SCSI, NFS, SMB/CIFS) and interfaces (PATA, SATA, SAS, FC, SCSI).

The updated article briefly describes DFS Namespaces and their conversion to Windows Server 2008 mode. It also discusses the DFS Replication feature. It mentions special one-way replication. Mostly discusses monitoring and control of replications. Different errors that occur and some solutions to fix them. Finally, Access-Based Enumeration is mentioned to hide folders that the user is not authorized to access.

The article briefly describes the basic configuration of a SAN network using Cisco MDS 9000 series switches. These use the Cisco NX-OS operating system. First there is a small introduction, then port configuration, VSAN and zoning. Finally, there are commands to display useful information. Knowledge of Cisco NX-OS or IOS and Fibre Channel (FC) technology is an advantage.

This article is a follow-up to the initial description of how to configure a Fibre Channel SAN using Cisco switches running NX-OS. Last time we covered the normal operation of the switch when it handles FC traffic. Today we will look at a special mode, called NPV mode, where the switch is used only to expand the number of ports and processing is done by another switch.

The article begins with a general description of iSCSI technology and SAN topologies. It goes on to describe the basic operations for running iSCSI Initiator on Windows Server to connect to a disk array and map a LUN (disk). Including setting up Multipath. The description focuses on Windows Server 2012 R2, but is similar on other versions of Windows Sever.

The article is primarily devoted to a general description of Fibre Channel technology and SANs based on this technology. This is followed by a description of what needs to be configured (which is almost nothing) to connect a Windows Server to a disk array via an FC SAN. The description covers the use of multiple paths with Multipath and the version of Windows Server 2012 R2.

A description of the basic operations to enable a connection from a VMware ESXi Server (iSCSI Initiator) to an iSCSI Target over a SAN. That is, connecting to a disk array and disk mapping (LUN), including setting up Multipath, and creating a datastore. The description is for VMware vSphere version 6.5, but is similar on other versions.

This article briefly describes the NetApp All Flash FAS disk array, namely the AFF8040 model. It discusses the main principles of function (without a detailed description of the technology), the necessary terms and possible configuration. It also describes common operations such as disk creation (LUN/Volume) and its assignment to a server, upsizing, and deletion.

Let's take a brief look at how to perform an ONTAP upgrade on a NetApp All Flash FAS (AFF) disk array, specifically model AFF8040. The process is simple, is done together for all components, and is failover free (as long as we have proper redundant networking). Finally, we mention the separate option to upgrade the firmware of the disks.

This article briefly describes the NetApp E-Series disk array, namely the E2760 model. It discusses the main principles of function (without a detailed description of technologies), necessary terms and possible configuration. It also describes common operations such as creating a Host and Volume and mapping them to each other (to assign a disk to a server), increasing the size and removing the Volume.

Let's take a brief look at how to perform a system upgrade on a NetApp E-Series disk array, namely the E2760 model. The whole process is more complex than the FAS series, we have to separately upgrade the SANtricity OS, update the SANtricity Storage Manager management application and also the disk firmware, NVSRAM and ESM firmware. The whole process should be fail-safe.

In the article, we will look at the types of cables used for LAN telecommunication networks (not only local networks, but also more extensive types of Ethernet networks) and data (storage) SAN networks. The same transmission media, cabling and connectors are used for both types of networks. We will focus on metallic and optical media (cables).

We will follow up on the previous article, which described the types of cables used for LAN telecommunication networks and data (storage) SAN networks, and describe the used connectors, Transceivers (converters) and Direct Attach (direct connecting) cables. We will again focus on metallic media (twisted pair) and optical media (optical fiber).

This article briefly describes the HPE 3PAR StoreServ Storage disk array, namely the 3PAR 8400 model. It discusses the main principles of function (without a detailed description of technologies), necessary terms and possible configuration. It also describes common operations such as creating a Host and Volume (LUN) and mapping them to each other (to assign a disk to a server), increasing the size and removing the Volume.

Continuing from the previous description of the HPE 3PAR disk array, we will look at several ways we can make copies of data. Create a volume snaphost, a snapshot in time that we can go back to. Clone a volume, a copy that we can use for testing, for example. And the most interesting part, if we have two 3PAR arrays in different locations, we can replicate the data from one location to the other using Remote Copy. If we add the Peer Persistence feature with Quorum Witness, we can build geographic clusters (metroclusters) where a site can go down without interrupting service.

The article tries to comprehensively, clearly, but briefly, describe the field of data storage with a focus on disk arrays. And network communication and the protocols used for it, primarily in the area of ​​SANs, i.e. iSCSI and Fiber Channel Protocol (FCP). This is a general description of how the server gets the disk from the storage system. Followed by a description of the implementation and differences in iSCSI and FCP. The article should provide some comparison between the two protocols, the general principle of which is very similar.

The NetApp array can log severity Alert events to tell us that hardware errors have been observed on a particular port on a particular node. There is not much detail here. The number of errors is said to be high, at least 1 in 1000 packets, but the real value is missing. There is also no specification of the error, it could be CRC, alignment, length or dropped frames errors. We will list how to find out more information and the possible causes of the problems.

The ONTAP operating system resides on NetApp AFF (All Flash FAS) and FAS (Fabric-Attached Storage) storage arrays. In this article, we will look at the physical and logical components that it uses to operate Storage. We will describe the network architecture, i.e., how clients communicate with the array. Then the physical and logical components that make up the storage architecture, how the data is stored. A major benefit of the ONTAP system is the Storage Efficiency features. We are able to store much more data (thanks to deduplication and others) on a certain physical space. Finally, we discuss the important area of how to make sense of the information displayed about the space occupied and available and the space saved due to efficiency.

Managing NetApp disk arrays running ONTAP can be done using the ONTAP System Manager web interface, but many more options are available using the ONTAP CLI command line. The commands allow us to configure and view everything in detail. In this article, we will look at commonly used commands and the implementation of some specific tasks.

EMS (Event Management System) collects events generated by the ONTAP system. It contains a large amount of traffic information about system states. It is important to be alerted immediately to system problems so that we can react quickly. We'll take a look at the options for viewing events and setting up to send selected EMS events (Notifications) to email. We will specifically describe setting up notifications for running out of space in aggregates and volumes (capacity monitoring).

Object storage is the youngest type of storage. They are often offered as a cloud service, but they can also be operated on-premises (as a special appliance or software on a server). In this article, we will look at a comparison of the main features with block and file storage. We will also discuss the general features and principles of object storage. A large representative of this type of storage is Amazon S3, which defines an interface for accessing the S3 REST API. Many manufacturers support this API and their solutions are referred to as S3 Compatible Storage / S3 Object Storage.