If you've not heard of "RAID", let me enlighten you.
Basically one can operate a computer with more than one hard drive. A lot of people already have more than one hard drive, but this is usually because a new drive has been added to overcome a capacity problem... too many music files or pictures, and more capacity is needed to keep the computer running. Often, also, an old drive is left in place as a slave to provide some sort of backup... usually a BAD idea because an old drive can slow a fast system down to a crawl.
RAID was originally introduced, because at that time hard drives were not very big and the cost of a really BIG drive in days of old was horrendously expensive. The answer was to make an array of smaller, cheaper drives. RAID 0 is the name given to the method that uses the array by spreading data across the set of drives in such a way as to make the user believe he has just one large drive. This is called "striping" and, if anything, can dramatically reduce the reliability of a system. RAID 1 is completely different however. This does not increase system capacity one iota, in fact it hides from the user a full 50% of available hard drive capacity by establishing a mirror of the main operating drive on a second drive of (usually) equal capacity. There are also other newer varieties of RAID such as type "5" now as well, but the type I chose for my updated system is RAID 1, wanting data security not extra capacity. Reliability mathematics give a neutral increase in data reliability for a twin drive RAID 1 configuration , but as most failures these days are rarely "end of life", being usually "random" failures, more to do with poor manufacturing, software or design problems, I don't think the theoretical 50,000 hours MTBF is ever likely to be achieved.
In theory RAID 1 lets me run my computer even if the main drive fails completely. At this point I would fit a replacement, and this would be automatically installed as a new mirror drive. Such is the design of a decent modern system, I could even remove the old drive and fit a new drive without turning off the computer, but this is more a feature of the design of the new serial hard drive interface and the physical design of hard drive power supply arrangements.
How does one go about the change to a new RAID 1 system, when one's existing system is running OK?
Bearing in mind that my hard drive carries a tremendous number of emails, huge numbers of music and picture files, masses of documents and spread sheets and the usual paraphernalia one would not like to lose, I firstly made a clone of the hard drive using a proprietary program. If anything went wrong at least I would have a copy of everything.
Which of these two statements is true?
In practice one can move an old hard drive to a new computer quite readily.
In practice one can move an old hard drive to a new computer only with extreme difficulty.
Both or neither is true and the reason depends on a multitude of reasons. I wish I knew what there all are, but I don't. Sometimes a new computer with an old hard drive will start up without a glitch, and other times one gets the dreaeded blue screen of death. Quite often the Registry is unreadable and the latter occurs. In practice there is a way round starting with a bad Registry, but this is not the case when data is not readable because of a major hardware change.
I try to limit the exercise to moving between either AMD chip-based computers or Intel chip-based computers. Mixing manufacturers can make things very tricky.
Rather than perservere and get round my blue screen once I'd fitted the cloned hard drive, I decided to start afresh with a clean operating system and a clean Registry.
Once this was done I copied the data from the old hard drive to the new computer.
This technique also got round the difficulty of making my RAID 1 system from an existing single hard drive system.
The original, more adventurous, plans went completely wrong however and that was the pragmatic solution I actually adopted...
I had an idea that I would establish a new RAID 1 system, remove one of the two drives and substitute for it the cloned drive from the old computer. I had in mind that I could fool the new computer to mirror the old drive rather than to wipe the old data and mirror the new. My MSI hardware didn't take kindly to the procedure however. At one point it told me I had three drives when only two were present. The original pair and the added one.
I identified and deleted the one I'd physically removed (no mean feat in itself as I couldn't identify which drive was which except by an almost hidden serial number). This left me with two, the new drive and the old cloned drive, however nothing I tried would convince the computer to mirror the cloned drive, and after trying several methods, ended up with a non-RAID system. At this point I decided to merely copy all the user data from the cloned drive to a new folder on the new drive. This, at least, had a nice clean Registry and Operating system already in place.
I then removed the cloned drive and added the second of the RAID 1 drives. Unfortunately the computer would not rebuild the RAID 1 system, stubbornly showing me two separate "non-RAID" drives.
The answer was to use a software method of building the RAID 1 system rather than the method using BIOS settings.
I installed and ran an Intel RAID utility from the Desktop, and this worked perfectly, mirroring and then hiding the second hard drive.
It only remains to be seen how things will progress....
A year or two later...
My Raid system went well for ages then, without thinking, I updated my MSI motherboard drivers. This is simple because a utility is provided by MSI which automatically fetches details of drivers and compares their issue status with those running. I selected motherboard BIOS and rebooted.... oops... I forgot to make a note of the original settings!
Unlike some manufacturers that ensure old BIOS settings are retained, MSI don't bother and by the time I'd discovered this it was too late. Every time I tried to boot up I got either a blue screen of death or a bad Raid system. In the end I compromised and re-installed Windows (over the top) and ended up with two hard drives... the main one plus the mirror.
I then read up about Raid and how to deal with problems. No luck I'm afraid as it's still a bit of a black art.
Eventually I had an opportunity to make some experiments.
I was building a new computer for a customer and had promised a pair of 500Gbyte serial drives operating in Raid 1.
Initially I installed Windows XP on a single drive.
I then identified the motherboard Raid chipset and made a floppy disk with which one can install a raid based operating system.
All went well. The method I chose was to use the Windows based Intel Raid software. A re-installation of Windows XP offers the opportunity to press the F6 key at the start of proceedings and, soon after, a prompt allowed me to load the correct ICH8 chipset drivers, then after some time I was rewarded with a Raid system (but flagged up as bad). No problem however, because one then starts the Intel Matrix Storage Console (supplied by MSI or from the Net) and, after an age, the mirror disk was up and running. I say an age because it must have taken the best part of 24 hours to mirror the main drive.
Having proved the principle I then considered the revamping of my own system. As I have the best part of 250 Gytes of data, mostly either not backed up, or rather out of date, I was not prepared to take chances so cloned the hard drive to a portable USB drive.
Carrying out a conversion from a single drive to a Raid 1 system this time turned out to be tricky. The reason was that I initially cloned the USB drive to a spare serial hard drive, but for some reason the copy turned out to be flawed and, try as I might, I just couldn't get the thing to work. After lots of attempts I ended up having to rely on the USB drive for a second time (but this time the USB drive had the only working copy of my precious data).
I tried lots of times to re-install Windows XP but failed until the penny dropped.
At the point where the system finally booted into the desktop with all drivers working, the motherboard BIOS was incorrectly selecting the empty hard drive as the main boot drive instead of the one carrying the cloned system.
The was tricky to diagnose because both drives looked identical to me (and the system). Once I'd discovered that the numeric sequence of the SATA ports was dictating which drive was boot drive, things got easier. Initially I'd (purely by chance) chosen Port4 for the cloned drive and Port 3 for the mirror. Once the Port 3 drive had been brought into the newly configured Windows system, even though it was freshly formatted, the MSI BIOS switched it to boot drive. This resulted in a blue screen of death.
I switched the two drives by swapping their data connectors and suddenly all was well and the system booted up. I then ran the Intel Matrix Storage Manager and, after several hours, everything was back to normal with drice "C" showing and what was previously drive "F" correctly disappearing.
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