The Small Computer System Interface Internet Protocol is IP-based, which means that ISCSI connects all the database storages developed by the IETF target group. The method is used to facilitate the transfer of information over intranets and to manage storage over long distances.
The ISCSI protocol is one of the key technologies that in the future will help to quickly develop the data storage market by increasing the transmission speed. Due to its ubiquity, the standard can be used to transmit over LAN, WAN, or the Internet and enable the extraction of data that does not depend on location, which means that ISCSI makes transmission speed fast
The principle of operation of iSCSI
When an end user or program sends a request, the OS generates the appropriate commands that go through encapsulation and, if necessary, encryption procedures. The packet header is created before the resulting packets are transmitted over the Ethernet connection. When a packet is received, it is decrypted, separating the SCSI commands and the request. Commands are sent to the SCSI controller, and from there to the storage device.
Since the standard is bidirectional, the protocol can also be used to respond to the original request and means that this ISCSI provides several approaches to transmitting information over networks.
The second method, Fiber Channel over IP (FCIP), converts Fiber Channel control codes and data into IP packets for transmission between geographically remote networks. FCIP, also known as Fiber Tunneling or Storage, is used only in conjunction with Fiber Channel technology and can operate over existing Ethernet networks. A number of vendors have already introduced ISCSI-based products, such as routers and routers.
The role of the information transfer protocol
To use traditional Ethernet networks to transfer information at the block level, today they use high-speed technology. This is iSCSI, which allows you to create high-speed connections.
Although SCSI is one of the oldest and most common protocols used for transmission over short distances, between the server and the storage device that are directly connected to this server. The term ISCSI means Internet SCSI or Internet Small Computer Systems Interface. IBM developed ISCSI in 1998 as a proof of concept and introduced the first draft of the ISCSI standard for the Internet Engineering Task Force (IETF) in 2000. The protocol was ratified in 2003.
ISCSI builds the protocol by encapsulating I commands and allowing these blocks of data to be transported over an unlimited distance via TCP / IP. The protocol describes how data blocks are transferred between the “initiators” in Ethernet networks and their storage goals. The role of initiators, goals, and components of iSCSI synology is required for the initial implementation of IP SAN. The initiator, as a rule, is the server hosting the application, where it periodically requests data on the corresponding storage device. Initiators are also called servers or host computers.
The iSCSI device driver that resides on the server can also be called the initiator. They “initiate” or begin ISCSI data transfer transactions, requesting the application to send / receive data from one or more storage devices. The application request is immediately converted to SCSI command, then encapsulated in ISCSI, where the packet and header are added for transport over TCP / IP over the Internet. Goals are one or more storage devices that are on the network. Targets receive ISCSI commands from various initiators or servers on the network.
On the target side, these commands are then split into the original SCSI format so that block data can be transferred between the initiator and the storage device. The target will respond to the request by sending commands back to this server. These commands are again encapsulated through an iSCSI drive for transport over Ethernet. The targets can be any type of database device, such as a storage array that is part of a larger IP or IP SAN. They can also be a separate tape library located either on the SAN or elsewhere on the network.
Best virtualization hardware
In order to connect ISCSI, TCP / IP networks are formed, because the standard uses the transport layer protocol, which describes how Small Computer System Interface (SCSI) packets should be transported over a TCP / IP network. Packets are transmitted over the network using a point-to-point connection. Upon arrival, the ISCSI protocol parses the packets, separating the SCSI commands so that the operating system sees the storage as a local SCSI device, which can be formatted as usual. Today, ISCSI in SMBs is about how server virtualization uses storage pools.
In a virtualized environment, the storage pool is accessible to all hosts in the cluster, and the cluster nodes interact with the storage pool over the network using the ISCSI protocol. Easy SAN Deployment iSCSI can use the same infrastructure as other computers on the network. Ideally, the two networks will work separately to avoid network congestion, providing a more practical approach to network planning for iSCSI.
This design can be scaled to provide multi-channel I / O by adding dedicated Ethernet switches for the storage network or allowing the production LAN to be used as a backup path if a dedicated Ethernet network is not available. The ISCSI initiator is a piece of software or hardware that is installed on the server to send data to the storage array on the ISCSI Windows Server and used in failover clustering.
The advantages of the Internet standard
Combining SCSI, Ethernet, and TCP / IP, iSCSI provides the following key benefits:
- Based on stable and familiar standards, many IT professionals are familiar with technology.
- Creates SANs with reduced TCO, installation and maintenance costs are low because the TCP / IP packet reduces the need for specialized staff.
- Ethernet transmissions can travel across the global IP network and therefore do not have practical distances. Provides a high degree of compatibility, reduces disparate networks and cables, and uses conventional Ethernet switches instead of dedicated Fiber Channel switches.
- Scales up to 10 Gigabits, OC-192 SONET (synchronous optical network) speeds are compared in urban networks (MAN) and wide area networks (WAN).
- Because it uses standard Ethernet, windows iSCSI does not require the expensive and sometimes complex switches and cards that are needed for Fiber Channel (FC) networks, making it cheaper to accept and simplify management.
- The FC Storage Area Network (SAN) transmits data without dropping packets and traditionally supports higher throughput. But FC technology is expensive and requires a special knowledge base for proper installation and configuration and can be implemented using conventional Ethernet network interface cards (NICs) and switches and runs on an existing network.
- Instead of training, creating and managing two networks - an Ethernet local area network for user communications and FC SAN for storage - an organization can use its existing knowledge and infrastructure for both LAN and SAN.
- Due to concerns about performance and compatibility with other storage networks, SAN iSCSI took several years to catch as the main alternatives to Fiber Channel.
- Creates SANs with reduced TCO, installation and maintenance costs are low because the TCP / IP packet reduces the need for specialized staff.
Security and disaster recovery
Organizations with changing data requirements, especially those that require storage security or disaster recovery, will benefit most from deploying IP storage and ISCSI. As productivity grows, iSCSI SANs are becoming widely used in enterprise TCP / IP networks. Distributing intelligent services and automatic resource allocation through virtualization will become an integral part of the evolution of SAN iSCSI networks. In addition, ISCSI represents a dramatic shift in the landscape of storage networks, giving IT managers another alternative to direct attached storage that provides the benefits of network attached storage.
The primary security risk for iSCSI SANs is that an attacker could spoof retrieved storage data. Storage administrators can take steps to block their ISCSI SANs, for example, using access control lists (ACLs) to restrict user privileges to specific information in the SAN. Call Verification Authentication Protocol (CHAP) and other authentication protocols provide secure management interfaces and encryption of data on the move and at rest.
Network storage services
Two iSCSI adapters are used in conjunction with standard NIC Ethernet networks through a Gigabit-enabled switch connected to an array of redundant, low-cost RAID (RAID) arrays supporting iSCSI. This configuration is suitable as the next step when upgrading to an iSCSI-exclusive SAN or as the initial SAN configuration. Multiple cards for a single router on separate servers can be shared with a Gigabit switch connected to an iSCSI-enabled router with Fiber Channel ports. Then it connects directly to the internal Fiber Channel RAID array. This configuration is also suitable as the next step when upgrading to a SAN interface with an interface to Fiber Channel storage devices.
The iSCSI adapter can be used in conjunction with a Gigabit-enabled switch connected to the router, with Fiber Channel ports connected to the Fiber Channel tape drive. This configuration can be used as a backup and recovery tool using your existing Ethernet infrastructure.
Networking with 10 Gb
ISCSI SAN is the ideal choice for users interested in migrating to network attached storage. Using the same block-level SCSI commands as direct application storage, iSCSI provides compatibility with user applications such as file systems, databases, and web services. Similarly, since it runs on ubiquitous and familiar IP networks, there is no need to learn a new network infrastructure to realize the benefits of SAN. To create a storage network in the data center, host bus adapters can be used on servers as well as ISCSI target storage devices using a combination of switches and routers.
SAN is the best choice for users interested in migrating to IP storage. ISCSI is another application for the network protocol stack. Thus, iSCSI is not only compatible with the existing network architecture, but also supports the same block level SCSI commands. This feature allows IT staff to move from a model with direct DAS connectivity to a SAN model. By adding storage traffic to an existing network, IT staff does not need additional training to manage networks for IP storage. In a typical data center, servers update / retrieve data from storage devices located remotely at gigabit speeds.
Consolidated storage simultaneously serves several servers. In the same environment, network traffic is processed at a speed of 1 Gigabit per second. IT staff have a difficult task to support the growing storage and network requirements. Configuring iSCSI on a storage network creates low latency and high throughput.
Deploying a Storage Network
SANs are growing rapidly because they solve the problem of reliable communications. This problem is caused by the need to manage large and ever-increasing volumes of disk storage. When the storage is directly connected to the computer using it through a high-speed cable, the storage device can very well satisfy the needs of this computer. When computers are networked, resource management is difficult or impossible. The SAN approach offers many storage management benefits, including:
- Backup without sacrificing performance for network users.
- ISCSI connection balancing the load on each physical device.
- Easily increases storage pool size.
- Easily share backup devices.
- Eliminates the downtime.
- Manages its computing resource separately from the storage resource.
- Manages his storage resource easily and efficiently.
- Shares the storage pool.
- SCSI and Ethernet standards are mature, stable, ubiquitous, and compatible.
These qualities provide a solid foundation for SAN implementation.
Ethernet connection
Basically, an ISCSI server consists of initiators and goals that will be used at both ends of an Ethernet cable. The initiator connects a computer that initiates a request for data stored on the disk using an Ethernet cable. An iSCSI target connects an Ethernet wire to a storage device, be it an array of disks or possibly a tape device. The initiator encapsulates the SCSI commands and data so that they can be sent via TCP / IP and the target retrieves the commands and data at the end of the storage device.
As with any network protocol, software that implements ISCSI using the TCP / IP approach is considered a layer. One or more of these software layers can be run on the host computer, on the coprocessor. The approach used determines the cost and performance of SAN connections. The best approach may be application specific, and the parameters may depend on the operating system used on the computer. However, although the potential benefits of a single network infrastructure for storing and creating networks are very large and lower the overall cost of ownership of the SAN.
Server and Storage Consolidation
With a network storage infrastructure, clients can associate multiple storage devices with multiple servers. This improves resource utilization, simplifies storage management, and simplifies the expansion of storage infrastructure.
Backup operations that were previously restricted to work over traditional file-level IP-based local area networks can now work across block-level IP storage networks.
This shift speeds up backup time and gives customers the flexibility to use shared or dedicated IP networks for storage operations.
With an IP-based storage network, customers can easily allow remote access to secondary sites via metropolitan areas or IP broadband networks. Remote sites can be used to back up, cluster, or mirror off-site replication. In addition, customers can select a link to storage providers for storage outsourcing applications, such as on-demand storage.
Enabling long-distance storage is essential for remote site backup or the implementation of reliable disaster recovery applications. The rapid introduction and expansion of IP data on the Internet has proven its viability to use IP addresses in long-distance networks.
Network Standard Users
ISCSI SANs are most suitable for enterprises that need streaming data and large amounts of data for storage and transmission over the network. This includes enterprises and institutions with limited IT resources, infrastructure and budget. Such organizations should look for ISCSI equipment that functions compared to standard category 5 Gigabit Ethernet copper cables. These include:
- Geographically distributed organizations that require real-time access to the same data.
- Internet Service Providers (ISPs).
- Organizations that require remote data replication and disaster recovery.
- Storage Service Providers (SSPs).
Thus, Internet SCSI (ISCSI) is a draft SCSI Transmission Control Protocol and Internet Protocol (TCP / IP) to enable I / O data transfer over IP. -, , .