The Silicon Graphics Legacy Of Supercomputers
SGI have an established reputation as an R&D powerhouse, creating powerful graphics workstations that created the effects for many blockbuster movies. Less well known are the high end servers and supercomputers that SGI develop.
When SGI purchased legendary supercomputer company Cray in the mid 1990s, they used some of Cray’s expertise, and developed their own range of monster super machines. The Origin 2000 was the first of these. Powered by MIPS processors, the Origin 2000 could range from 8 CPUs up to 1024. Adding special graphics cabinets created the Onyx, a graphics supercomputer of extreme power.
Then SGI created the Origin 3000, expanding on the original design. The Origin 3000 used modular ‘bricks’ - containing processors, IO cards, or even graphics cards - to allow very customised configurations. Again, ranging from 8 CPUs to 1024 - with rumours of extreme 2048 CPU machines being built for government agencies.
These servers were Single System Image (SSI) servers. Despite the large number of processors inside them, they ran one copy of the IRIX operating system, and behaved to the end user exactly the same way as a desktop compuyter would.
SGI are continuing their development with the current range of Altix scaleable supercomputers, based around Intel’s Itanium CPU and running Linux. With multi-core Itaniums available stories abound of massive 4096 core SSI systems hidden away in government labs.
Tape Imaging Software,
When you have backed up every single night for the last 5 years, then you find that when you need the backup, you discover the tape wont load because of a tape error.
So what can you do. There are lots software options for backup data recovery, but most of these only work on backup files, so how do you recover data from a tape?
Data Recovery Engineering Software Limited write software mainly for data recovery companies, and one of their titles is a very affordable tape dumping tool.
The software creates an image file of the data on the tape to hard disk. Now you can access the data on the tape and recover it with your backup recovery software.
Other uses are when someone has created a backup set that you need to access, but it is password protected (not encrypted) and the user cant remember the password or left the company. Or a forensics examiner needs to look at the data stored on the tape but does not have access to the software used to make the tape.
Recovering Data From Hard Drives
Overview
Modern computer system hard disks can contain a vast amount of data. So when your hard disk fails, and there are no recent backups available, data recovery is the only option available.
Introduction
A hard disk consists of a number of component parts. Each of which has its own failure modes.
1. Electronics
2. Mechanics
3. Firmware
4. Logical
Electronics
The circuit board on a hard disk is the ‘brain’ of the hard disk and a single component failure will render the drive useless. Data recovery from hard disks with electronics failures will require highly skilled electronics engineers who can to make temporary repairs in order to recover the data.
There are also electronic parts inside the hard disk that are vital for the correct operation of the hard disk and consists of the head pre-amplifier circuit.
Mechanical
The critical mechanical parts of a hard disk comprise of, the actuator arm, the motor and the platters. (There are other Mechanical parts, vibro-acoustic components, filters, VCM Magnets, etc, but these are less critical).
The majority of mechanical failures involve the Head pre-amplifier. Whilst this is not exactly a mechanical failure, the method that the head pre-amp is fixed to the head stack means that when it fails it involves the replacement of the entire head stack assembly.
The next biggest cause of failure is motor failure. This is probably the most serious problem and requires specialist equipment so that platter alignment is not lost when removing and replacing the motor. Main problems with motors are burnt out coils and seized bearings.
Firmware
The firmware area or System Area (SA) is a region on the hard disk that contains the manufacturer’s proprietary information such as
- Grown Defect Maps
- Head maps
- Operational code
- Self test logs
- ATA Password Information
- Security Data
- SMART Logs
- Translator Tables
and many others
For a hard disk to work properly it is vital that the Firmware Zone is error free. Fixing the Firmware on a hard disk is a highly skilled job and requires specialist equipment. Making a mistake when modifying the information in the Firmware of a hard disk can render a drive useless.
Logical
Logical problems are where there is nothing physically wrong with the hard disk and it is fully functional. Logical problems are where data has become inaccessible for some reason, for example, the user has deleted the files, the computer has come under virus attack. The skill set of the engineer requires knowledge of how the operating system that the data was stored on works. Also, an understanding of the file format for different file types so that quality of files can be determined on a bulk and individual basis.
Data Recovery from Hard Drives
MjM Data Recovery Ltd
