Storage Technologies in the Wings

Once upon a time, the organizations had plenty of time and capacity or face

it that the needs were limited. Backups could be done at night when the systems

were not loaded or were shut down. But since then, the needs have crossed the

roof, systems work around the clock and so do the users, and there's no period

when you can shut everything down for backup. Today, an organization needs to

store all kinds of data. There are different time periods for which you want to

store this data based on its utility to the organization and regulatory needs.

And then you have storage devices lying around that've been exhausted or are

soon going to be all filled up.

All this makes it necessary that there be better storage devices that are

more capacious and faster. For this, researchers have been continuously

exploring new technologies or improving existing ones to help you store a larger

amount of data, for a longer period of time. And all this in a manner that you

do not have to pay exhorbitantly compared to what you do today. The new

technologies should be such that you have to do minimum change in the existing

infrastructure. Some of these include virtual tapes, 4GFC, Blu-ray, HD DVD,

serverless backup, perpendicular recording, PSAN, 3D and online storage that are

standing the wings to join the bandwagon.We take you through the technology

behind each and promises they make for the future.

Perpendicular recording

Let us get down to the basics. More things can be packed in a space when they stand up rather than when they are lying down. And that's the reason why perpendicular recording is in vogue. Perpendicular recording aligns the bits perpendicular to the disk, which allows you to fit in more data into the same space, at higher recording densities. This technology is expected to increase the capacity of hard drives as much as 10 times. It is the saturation in the longitudinal recording capacities that has led to this innovation to counter superparamagnetism. Superpara-magnetism is a phenomenon that causes interference amongst the magnetic grains that make up data bits when they are packed beyond a certain density on the disk. As a result, the grains lose their orientation leading to corruption of data on the storage device. Seagate has been the pioneer in using this technology by launching its 2.5 inch, 160 GB drive for notebooks. The latest we've received for evaluation is the Seagate Barracuda drive with a whopping 750 GB capacity. Hitachi is also backing this technology. At this speed, we will soon have 3.5 inch disks storing terabytes of data.

Virtual tape library



Tape has always been the preferred medium of backing up data permanently and its
benefits have been numerous. For instance, with tape you get to store data

off-site for a longer period of time that you might need it for. Not only that

you can restore all data lost or deleted from the machines in use. This is

contrary to how the hard-drive storage works. Here the data stored, used as well

as unused, all lies on the machine you are using. While this simplifies the way

you can access the data (tape stores the data sequentially while the disk does

it in random fashion), it is a costlier option compared to the tape-based

storage, both in long as well as short run.

But that's only one side of the coin. Disk-based storage hasn't lost the

battle for the advantages it has over tapes. It is faster, and is easier to

handle when you want to work with and restore data. To add to it, disks offer

online storage unlike tapes that need to be kept separately once the data is

backed up on them.

In the light of advantages and disadvantages that each one has, researchers

had been struggling to find out a workaround. And they have succeeded in having

the cake and eating it too-with virtual tapes. Virtual tapes combine the power

of both the tapes and disks, in a manner that lets you reap the benefits of

both. Virtual tapes emulate (behave, look and feel) like a tape, though they are

actually disks. In action, the back-up software sees the VTLs (Virtual Tape

Libraries) as physical tape libraries to perform backup operations. As a result,

while the data is written in a sequential format (as in tapes) on the disks that

emulate as tapes, it is backed up almost 10 or more times faster than the real

tape. Also, you are saved from the hassles of rotating, handling and storing

tapes.

It requires almost negligible or no changes to the back-up processes,

schedules and workflows. While it still doesn't solve the inherent problems of

storing the data offsite to be used in case a disaster strikes, VTLs can be used

as faster alternatives to store less-used data that can finally be moved to real

tapes whenever needed.

FC and iSCSI



iSCSI, for a long time, was perceived as a better, low-cost storage

networking protocol compared to the Fiber Channel. But today iSCSI has emerged

as an entry level for SAN interface. On the other hand, the FC (Fiber Channel)

is apt for operations that involve connecting servers to shared storage devices.

Most iSCSI based storage area networks use 1 GB Ethernet unlike the FC that has

touched 4G capabilities. The 4GFC products are well suited for high-bandwidth

applications such as voluminous data backups, streaming media and transactional

processing.



Either technology is well suitd for specific needs. To understand this, if a
less amount of data is to be processed, both technologies serve the purpose (but

FC loses out to iSCSI due to its price and difficult deployment process here).

On the other hand, if more data is to be handled, iSCSI's speeds create

bottlenecks.

Serverless backup

When a backup is in progress, your servers-the source and the backup servers-are the most stressed. During this time they consume a significant amount of CPU cycles and memory. The solution A good option is to offload these servers of this extra load during backups. The process is referred to as serverless backup, and is a SAN based solution. This is done when you use a data-mover device that initializes the back-up process to copy the data directly from the source (say, a hard disk) to the destination device (back-up devices). The data mover may be implemented in a switch or a router. There are products available in the market that have the serverless back-up option that leverage SNIA's Extended SCSI Copy command to significantly enhance performance by taking the backup load off servers and freeing CPU time for other mission critical tasks. When to consider While there are such high-end backup solutions offered by companies like Legato, Veritas, Computer Associates and IBM, it is not always necessary that you have to switch to the new ways. Instead, your decision should be based on your priorities, peak hours and type of data that you need to back up. For instance, if you need to backup the mailboxes of all the employees across the organization, you need not do that in office hours when the servers are loaded with other processes. You may go for such solutions if your business needs include: Frequent backup and restoration of huge amounts of data Backup during office hours and, Your priority is server performance

3D storage



Imagine writing data across a volume of space rather than on a two-dimensional
media. This means the same area can be used to store more data. This is the idea

behind 3D storage. Here, you are not only using the x and y dimensions but also

z-axis to store data.

A hologram is formed on a photo-sensitive recording media at a place where

the reference beam and the signal beam carrying data intersect. Holography has

the potential for fast transfer rates and fast random access times. This is

because the data are stored and recovered in parallel-typically 1 million bits

at a time.

Experts predict that in a few years we'll eventually be able to store

terabytes of information in a space no larger than several CDs stacked on top of

each other. That's the promise of holographic storage. For more on how it works,

refer to Enterprise Storage Technologies: the way ahead, in our March 2006

issue.

HD DVD vs Blu-ray



While the debate on which one will take the market by storm is quite old now, it
is still hot. If it is only price that will govern who will dominate the market,

then the verdict tilts in favor of HD DVDs. But if the battle is out for higher

storage capacities, it will be Blu Rays' turn. Both HD DVDs (High Definition

DVDs) and Blu Ray disks use shorter-wavelength blue laser to read and write

data. The two are heavily backed by different industry giants.

Blu-ray is backed by Sony while HD DVD uses another technology called the iHD

that Microsoft and Toshiba have worked on. A dual-layer HD DVD packs around 30

GB data on it as compared to the 50 GB (around one and a half times) by Blu

rays, which is by no means small. We have to watch out for some time before

judging which one wins.

P-SAN



Here is a disk-based backup storage technology with which you no longer need to
use fiber-optic cabling to connect SAN components. P-SAN is a storage system

developed by JMR Electronics with the capability to connect to the network as an

extension of the standard PCI bus on personal computers. It uses a PCI switching

architecture to work as an extension of the JMR's PCI bus using CA's

BrightStor ArCserve backup solution. Instead of fiber-optic links, the

technology makes use of IP storage. This means that it uses TCP/IP and standard

Cat 5 cabling to connect to the network. It can scale up to large capacities at

an optimum cost, making it a perfect alternative to tape or other costlier

disk-based systems.

Online storage



This is an interesting option that organizations and individuals can explore
alike and there are already more applications than you might first realize.

There are sites that offer a ID/password protected space on the Internet where

you can store your files. Your space can only be accessed by you or by someone

you want to give access to. Today many such services like Foldershare, Bitvault,

Xdrive and iBackup are already operative that give you both paid and free

storage space online. While they give a small amount of storage space for free,

say 25-50 MB, they have paid services for



organizations that would need larger storage space. Some sites offer true group
collaborative functions as well. This way you can access your data from any

computer if you have Internet access and a browser. Though individuals are

currently using most of this online space to store data, organizations can also

benefit from it once these sites integrate efficient security mechanisms within

their services. Its not over yet. As demands on capacities continue to explode,

new technologies will rise up.

Rinku Tyagi