Harness The Power Of Virtualisation

Sunday 4th October 2009

Or, as our Americans cousins like to say, "Leverage your assets!"

Provided that, in accordance with the recommended practice, you are running your servers on "modern hardware" rather than "ancient skipware",  they could well be massively under-utilised.  What tends to happen is that old servers are replaced with new servers on a one-for-one basis.  Even though the workload may not have increased significantly, the specification of the new machine is usually considerably greater than that of the old one. 

Virtualisation is a great way to consolidate multiple servers onto a single physical machine, provided that it is sufficiently powerful to support the workload required.  This means that fewer machines are required, thus giving cost and space savings.  However, these befits come at a price.  In this case, the downside is that of putting "all your eggs in one basket".  At one extreme, a complete duplicate server may be needed to ensure business continuity in the event of a failure, whereas at the other end merely a RAID-5 disk array may be necessary.

With virtualisation, backups become both easier and even more important than otherwise.  Because a virtualised server is effectively a single disk file, it can be backed-up much like any other disk file.  Equally, were it to be become damaged, it will often be impossible to repair and it must instead be restored from backup.

Just remember that, as in every other aspect of life, "Every coin has two sides".  It is, therefore, quite impossible to enjoy the benefits of virtualisation without the associated costs.  The trick lies in ensuring that the former considerably out-weigh the latter!

Are You Running Your Business-critical Systems On Skipware?

Sunday 27th September 2009

Then you deserve the Victoria Cross for bravery!

As any piece of mechanical equipment ages, the risk of it failing will naturally increase.  Eventually, the risk will become unacceptably great and the equipment should be replaced.  Who would expect a salesman to use a 10-year old car with 300,000 miles on the clock?  Servers are normally expected to run 24 hours a day, 7 days a week.  After three or four years' continuous running, dust and dirt will have built up around the internal components.  This will interfere with the free circulation of air and thus cause them to run at higher temperatures than their manufacturers intended.  This, in turn, will increase the risk of failure, especially as the bearings in disk drives etc will also be wearing out.

Such equipment is really fit only for recycling and should be replaced,  Modern rack servers are able to provide far more processing power and storage in a 2U space than the pedestal servers of even three or four years ago.  They are also less noisy, use less power and generate less heat.  Best of all, they are not likely to fail any time soon!

Due to its shape and size, a pedestal server will waste a great deal of space in a data cabinet.  By contrast, a rack server is much more compact.  Since servers are optimised for a long and hard-working life, they tend to be noisy.  A desktop PC, on the other hand, is designed to be as quiet as possible.  Noone wants a server anywhere near their desk or even in the same room, but putting one in a data cabinet, even if it is not the acoustically-baffled type, will usually reduce the noise level to an acceptable level.

Apart from issues of reliability, size, noise and environmental considerations, modern servers come with excellent management facilities.  Typically, these enable remote access to the server for monitoring, configuration and access to the BIOS.  Since it is no longer necessary to visit the server in person for such functions, its physical location becomes relatively unimportant.  With the high cost of office space, the ability to fit a server into an empty rack in a data cabinet is a further bonus.  After all, a data cabinet will already have the networking equipment needed to support the server and will usually be able to supply the limited power required by most modern rack servers.

Enterprise-scale servers are rather different - they are, almost by definition, physically large, noisy and power-hungry.  However, they are normally installed in an air-conditioned data centre, along with many others of the same type.  In that specialist environment, factors such as noise are largely irrelevant.

Seen In The Window Of A Charity Shop - "Don't Dump It - DONATE IT!"

Sunday 20th September 2009

However, some people seem to take this too literally...

One of the problems faced by Charity Shops is that they are sometimes regarded as a convenient convenient alternative to the local Council tip.  What use could they possibly have for worn-out clothing, broken toys, jigsaws with pieces missing, etc.?  On the other hand, it is well-known that we live in a society where waste is endemic.  If an item is merely unfashionable or unwanted, it may often be thrown away, even if it is still perfectly serviceable.  Stories abound of the items found in skips, discarded by their owners as valueless.  A PC which is, say, five years old will probably not be able to run Vista.  However, it will usually be perfectly adequate for simple activities such as surfing the Internet, sending emails or watching the BBC's iPlayer.  Although some Charity Shops are unable to accept electrical items due to safety regulations, many can and do.  Such a PC may sell for £10 or even £15 - quite a useful contribution to the Charity's funds.

Before handing over a PC, it is vital to check whether it is is in good working order.  If it is, its hard disk should be wiped and a fresh copy of the operating system installed.  It is not usually necessary to use a data shredder first, unless it contains especially sensitive data.  A non-working PC, on the other hand, should be taken to the Council tip, but not before its hard disk has been physically destroyed with, for example, a hammer.

There is actually a third way to dispose of old or unwanted items, including PC's.  The "Freecycle" network does a sterling job of linking would-be donors with would-be recipients.  Its home page is at http://www.uk.freecycle.org/ and there are local groups throughout the country.  Its two main restrictions are that no living creatures, including humans, may be offered and that everything must be free.  Each group has a different character, with those in metropolitan areas tending to offer items such as furniture and household goods, while lorry-loads of compost are quite commonly seen on rural groups.

Freecycle is definitely worth a look, if only for the sake of idle curiosity.

Prepare To Bid A Fond Farewell To The CD....

Sunday 13th September 2009

.....and the DVD is not too far behind it!

The earliest floppy disks were 8" across and they really were "floppy".  They would still work perfectly well even after people had folded them in half and put them in their pockets.  The typical capacity was 128KB - laughable in 2009, but surprisingly useful in the days before graphical interfaces, colour screens and the rise of "bloatware".

After 8" disks, 5.25" disks were developed, with a maximum capacity of 1.2MB.  These were housed in a paper cover but were only slightly flexible and would no longer survive being folded in half.  The final incarnation of the "floppy" disk was 3.5" across with a rigid plastic outer shell and a maximum capacity of 1.44MB.  After a 20-year lifespan, 3.5" floppy disks have finally become obsolete.  Blank disks are still available, but the drives have not been fitted in new computers for a while now.

DVD drives and blank disks are now very cheap and even the lowest-capacity DVD holds the equivalent of six CD's.  Admittedly, Blu-Ray disks can hold rather more data, but even they are about to come under pressure from Memory Sticks, which have a number of advantages.  As well as being much more compact, they need only a normal USB port, which is far smaller than a DVD drive.  In addition, they have no moving parts and use almost no power.  As yet, Blu-Ray disks still offer a higher capacity, but that will not be the case for very long.

As usual with computers, hardly has one new technology arrived before it is displaced by another which is better/larger/smaller/lighter/faster etc. as the case may be.  You've guessed it right - Blu-Ray is next.....!