Failover at multiple level in storage networks

Storage networks can be broadly classified into 3 levels and the fail over or Redundancy feature is very important aspect of IT storage business and it is implemented in every interconnecting components in the networks.
Host or Server(s) Level
Network Level
Storage sub-system(s) Level

Fail-Over:
If the data passage path of any of the component in the storage networks fails, the auto-mechanism that provides an alternate path instantly to avoid the data loss is called fail-over.
Example: If a component such as a RAID controller module or a cable fails, or an error occurs on the data path to the preferred RAID controller module, virtual disk ownership is moved to the alternate non preferred RAID controller module for processing. This failure or error is called failover.

Host or Server Level:
Hosts or servers are associated with few interconnect peripherals such as Host Bus Adapter [HBA], Ethernet adapters et al. some common fail-over feature implementations that you see is at the HBA device in the form of Fail-over driver such as MPP or MPIO [Multi Path driver].
Another stage of fail-over implementation could be to the entire host or server in the form of Clustering, Microsoft Clustering or Linux or Solaris or Unix clustering.

Network Level:
At Switches or Routers, we can provide fail-over by connecting one port or path of the servers & storage sub-systems to one switch port & another port or path connected through another switch port. thus we need at the least two switches to handle the Preferred path & Alternative path of data passage.
usually such setups are know as High Availability Fail-over setup.

Sub-system Level:
Within the SAN storage sub-systems, there are multiple components such as RAID Processors or controllers, Hard disks, Drive trays, power supplies et al.
At Hard disk level , RAID & Hot sparing is used in co-operation with RAID processors as fail-over.
At Drive tray or Enclosure level, there will be dual Service Modules that act as fail-over.
At the RAID Processor or Controller level, there will be Dual RAID processors or Controllers that provide fail-over mechanism.

Fail-over is very vast concept and there are plenty of ways to implement it at different components of the storage networks. for more information you can always buzz me on Email.

Latest Storage market status - Q2 2008

HP, IBM, Dell, SUN are all top global enterprises with broad range of products, here i have current market status for these companies in External Storage segment only.

According to analyst group IDC, Despite tough conditions in the U.S. economy, which have decreased demand for everything from new homes to semiconductors, the market for computer data storage Relevant
Products/Services systems is going strong.
EMC continued to lead the external disk storage systems market with 21.7 percent of the revenue share, followed by IBM at 13.1 percent, HP at 12.9 percent, Dell at 9.2 percent, NetApp at 8.0 percent and Hitachi at 7.6 percent. Of the top five suppliers, EMC and NetApp posted the strongest year-over-year revenue growth at 19.7 percent and 17.2 percent, respectively.
The Open SAN market grew 15.5 percent year-over-year, with EMC leading with 23.9 percent of revenue share, followed by HP at 16.7 percent. The NAS market experienced year-over-year growth of 23.5 percent, with EMC leading with 39.8 percent of revenue share, followed by NetApp at 28.5 percent. The iSCSI SAN market showed year-over-year revenue growth of 93.9 percent, with Dell leading the market (due to its acquisition of EqualLogic) with 32.8 percent of the revenue share, followed by NetApp at 14.6 percent and EMC at 14.1 percent.

**********for more information check out http://www.echannelline.com/usa/story.cfm?item=23687 *******************

IBM Storage Products

NOTE: IBM has comprehensive range of storage hardware & software products such as servers, SAN, NAS, Switch, Tape libraries, switches & SAN arrays, NAS devices etc. so here am listing only few storage specific products.

IBM Disk storage subsystems
Enterprise systems - DS6000 and DS8000 family
DS6000 series
DS8000 series
DCS9550

Mid-range systems - DS4000 family
DS5000
DS4800
DS4700 Express
DS4200

Entry level systems - DS3000 family
DS3200
DS3300
DS3400

Enterprise SAN directors [High end switches]
For highest availability and scalability enterprise solutions.
IBM System Storage SAN768B
IBM TotalStorage SAN256B
IBM TotalStorage SAN140M
IBM TotalStorage SAN256M

Mid-range SAN switches
For scalable, affordable SMB and enterprise solutions.
IBM System Storage SAN80B-4
IBM System Storage SAN64B-2
IBM System Storage SAN40B-4
IBM System Storage SAN32B-3

Entry SAN switches
For simple, affordable small and medium business (SMB) solutions.
IBM System Storage SAN24B-4 Express
IBM TotalStorage SAN16B-2

IBM Express Model SAN switches
For affordable, simple-to-use small and medium business (SMB) solutions.
IBM System Storage SAN24B-4
IBM TotalStorage SAN16B-2

Tivoli Storage Manager
Manage risk through complete storage management with enhanced performance and access for Sequential Disk. Manage complexity with encryption key management. used by more than 21,000 customers.

OEM Storage Management softwares
Basically OEM storage product software marketed with IBM logo.

IBM TotalStorage Productivity Center
Identify, evaluate, control and predict the growth of data through its lifecycle to meet storage service levels.

IBM System Storage Virtualization
Designed to help simplify storage infrastructure, optimize storage utilization, and enable business to adapt quickly and dynamically to variable environments

HP Storage Products

NOTE: HP has comprehensive range of stroage hardware & software products such as servers, SAN, NAS, Switch & HBA software, HBA's, switches & SAN arrays, NAS devices etc. so here am listing only few storage specific products.

Disk Storage Systems [SAN]

XP Disk Array - High Level
[HP StorageWorks XP24000 Disk Array, XP20000 Disk Array, XP12000 Disk Array, XP10000 Disk Array]
• Bulletproof storage for 24x7 business continuity demands
• Massive consolidation for greater efficiency
• Virtualization platform for internal and external data

EVA Disk Arrays - Mid-level
[HP StorageWorks Enterprise Virtual Array 8100, EVA6100, EVA4400, EVA4100 & EVA Software]
• Powerfully simple enterprise class storage
• Affordable and virtualized storage with a low entry price and low total cost of ownership
• Reliable and available

MSA Disk Arrays - Entry level
[HP StorageWorks Modular Smart Array 2000sas, MSA2000fc, MSA2000i & Storage Resource Management Software (SRM)]
• Flexibility to start small and migrate drives & enclosures into larger configurations
• Increase server capacity
• Modular design enables expansion

NAS Systems
[HP All-in-One AiO1200r SATA, AiO1200r SAS, AiO600, AiO400t, AiO400r,AiOSB600c]
• Unbelievably simple: No storage expertise required
• Uniquely affordable: A complete storage solution
• Unquestioningly reliable: Integrated data protection and HP reliability

Scalable NAS

• Scalable, Available Enterprise NAS
• Windows and Linux File Serving
• Oracle over NFS, Microsoft SQL Server Consolidation

Switches
B-series [Fabric switches, Blade switches, Director switches]
• B-series switches and directors are used by small departments and global organizations to access and share data in a consolidated, manageable, and a scalable manner.
C-Series [Fabric switches, Blade switches, Director switches]
• C-series family of multilayer directors and fabric switches is a comprehensive line of SAN switches that provides an effective way to access, manage, and protect growing information resources.
• C-series switches are basically CISCO switches marketed by HP.

HP Storage Software

• Storage Resource Management Software (SRM)

• HP StorageWorks EVA Device Management Software
• HP StorageWorks EVA Replication Software

• HP StorageWorks XP Replication Software
• HP StorageWorks XP Device Management Software

• HP Storage Data Protection and Recovery Software
• HP StorageWorks Storage Replication Software
• NAS Device Management Software
• B-series Switch Device Management Software
• C-series Switch Device Management Software

Web based Storage & Virtualization Training

NOTE: this blog post is borrowed from other sites. just for the sake of readers request " FAQ: any training centers available in storage in Bangalore?".
Learning through Videos is the fastest & most effective method after learning from an instructor or a personal trainer. Cost of a personal trainer is high to learn Storage technology hence a team I know very well is developing a website for Storage fundamentals + SAN training using Videos. Learning from Videos that too Web based videos has advantages like
- you learn at your own pace,
- you replay the video & see it number of times to perfect the concept or technology

A separate website is being developed by a team of Storage professionals who will be Sharing some of their industry experiences,
Giving you tips for a Career in Storage technology
But main focus will be to give you a Strong Fundamental knowledge on Storage technology

The topics covered will be around(This is just the initial list I got they promised that it will grow more soon, lot more will be covered)
Storage Basics
SAN(Storage Area Network): SAN components
SAN Hardware
SAN Software
SAN Configuration & Troubleshooting overview
iSCSI (SCSI over IP)
FC (Fibre Channel)
Storage connectivity & interfaces:SCSI,SAS,SATA & more.


There will be huge bonus additional Videos & materials like
- What to expect in Storage job interviews
- Tips to prepare your resume to get more interviews from Storage companies
- Tips for interview preparation for Storage technology job openings
- Tips for prioritizing what to give importance & which topics you need to perfect
- You will receive 300+ interview questions from different Storage company interviews which itself is valued at $100. You get this free when you join for this Video training membership website.

Cost for this web based training access will be $500 (USD) payable through paypal or credit card. Those who are interested please email semiconsys@gmail.com today & confirm your interest. The access to this membership based website will be limited only to few since the website development team wants to work more closely with the members & provide some additional value adds, hence I would recommend you to email today & confirm your interest to join.

You will soon get to see a preview Video from their list of Storage Technology Videos on this blog. You will also see lot more updates about this new website being developed soon on this blog.May be I will post some of the reviews or Videos from members who joined & benefited from this web based training website.

Storage Subsystems - implementation in SAN

********If anyone need expert consultation, do send me email at storagetrendz@gmail.com************************

* The storage components of a SAN are the storage arrays. Storage arrays include storage processors (SPs). The SPs are the front end of the storage array. SPs communicate with the disk array (which includes all the disks in the storage array) and provide the RAID/LUN functionality.
* Storage Processors or Controllers:
SPs provide front-side host attachments to the storage devices from the servers, either directly or through a switch. The server HBAs must conform to the protocol supported by the storage processor. In most cases, this is the FC protocol.
* Storage processors provide internal access to the drives, which can be using a switch or bus architecture. In high-end storage systems, drives are normally connected in loops.
* This back-end loop technology employed by the SP provides several benefits:
# High-speed access to the drives
# Ability to add more drives to the loop
# Redundant access to a single drive from multiple loops (when drives are dual-ported and attached to two loops)
* Storage Devices
Data is stored on Hard disk arrays or tape devices (or both).
Disk arrays are groups of multiple disk devices and are the typical SAN disk storage device. They can vary greatly in design, capacity, performance, and other features.
* storage array uses RAID (Redundant Array of Independent Drives) technology to group a set of drives.
* A LUN is a single unit of storage. A LUN is also known as a volume or Virtual Disk or a logical drive, A RAID Group is one or more LUNs with specific RAID level defined.
* Most storage arrays provide additional data protection and replication features such as
snapshots, Clone copies and Remote mirroring.
# A snapshot is a point-in-time copy of a LUN. Snapshots are used as backup sources for the overall backup procedures defined for the storage array.
# Clone copies are actual copy of a LUN, it allows data movement from one LUN to another for an additional copy for testing.
# Remote mirroring provides constant synchronization between LUNs on one storage array and a second, independent (usually remote) storage array for disaster recovery.

Host Bus Adapter [HBA]

* HBA is an important component of Storage networks, especially in SAN architecture.
* HBA is usually host-side component & can be connected to PCI or PCI-X or PCI-E slots on the host or servers. it provides the crucial connectivity between Hosts-StorageSubsystems in Direct attached setup, provides connectivity between Host-FabricSwitches-StorageSubsystems in SAN environment.
* HBA vendors are very few, some vendors provide HBA management software & drivers along with HBA (ex: Qlogic, Emulex, Brocade etc).
* HBAs available in market may be of Fibre Channel (FC), SCSI, SAS and iSCSI interfaces.
* HBA comes in different priceband and the difference in price band is largely driven by the number of ports. HBAs are available in the market with single port, dual(2) Ports, Quad(4) ports, octa(8) ports etc. Depending on the number of Ports & the type of interfaces, the HBA cost varies from 500$ to 5000$ or even more.