To RAID or not to RAID – That is the Question

[Magnets]

MG]
Enable Write back Cache by right clicking on the desired volume & selecting it in the menu.

i would beware of this, i googled it and it seems it only writes to the disk cache, and doesn't wait for it to be written to the HDD. So if you fill your cache, and you lose power, that data in cache will be lost!
Have i interpreted that correct?

clicky

[Supershanks]

So if you fill your cache, and you lose power, that data in cache will be lost!
Have i interpreted that correct?

Yep i think you have but for the slight chance of that it's worth the risk imo.
Shows the impact of writeback cache enabled(blue) disabled(red)


Again it's down to the individual but it might well be that if you are so concerned at that , you wouldn't be using raid in 1st place.

[EtheAv8r]

Thanks again Supershanks. I will 'play' , err investigate....

There is a small risk of data loss or corruption with any power loss, and this may be somewhat greater with a RAID... but we spend hundreds on our systems and a £60 UPS will protect against such events.....

[shaithis]

The argument that RAID 0 is bad because if one drive goes bad you lose data is irrelevant, the same holds true for data held on a single volume, this is a backup issue, not a RAID 0 issue.

That's a very simplistic view of things....

A raid0 array of n drives has n times more chance of losing its data then a single drive.

Also, if anything bad does happen to a single disk, you have an infinitely greater chance of recovering information from that drive then you would with a raid0 array.

Just food for thought.

[Steve B]

In RAID0, dont you lose all the data if one drive fails?

[Supershanks]

In RAID0, dont you lose all the data if one drive fails?

Yes hence the reason i describe having my documents & settings on another drive. I take a daily image of my raid0 so only really lose any install/removals or updates , alll of which can be easily recovered. Asa i said earlier

The main danger is going into it without planning for data security

luck

[Blitzen]

I RAID 0 and i love it.
If you back up regularly then there is nothing to worry about tbh.

My RAID 0 Maxtors are outperforming a single Raptor according to HDTach and i got 2x200gb ones for more than half the price of a single Raptor.

[EtheAv8r]

That's a very simplistic view of things....

A raid0 array of n drives has n times more chance of losing its data then a single drive.

Also, if anything bad does happen to a single disk, you have an infinitely greater chance of recovering information from that drive then you would with a raid0 array.

Just food for thought.

Well yes, and I like to keep things simple.

The most common specification related to drive reliability is mean time between failures or MTBF. This value, usually measured in hours, is meant to represent the average amount of time that will pass between random failures on a drive of a given type. It is usually in the range of 300,000 to 1,200,000 hours for modern drives today (with the range increasing every few years) and is specified for almost every drive.

This number is very often misinterpreted and misused. Usually, the "analysis" goes like this: "Gee, a year contains 8,766 hours. That means my 500,000 MTBF drive should last 57 years." (I have even seen this on the web site of a major hard disk manufacturer that shall remain nameless to spare them the embarrassment!) After concluding that the MTBF means the drive will last for decades, amusingly, one of two opposite things usually happens: either the person actually thinks the drive will last half a century or longer, or the opposite: they realize this is crazy and so they write off the entire MTBF figure as "obvious exaggeration and therefore useless". The real answer of course is neither. (It is obviously impossible for any individual hard disk to be tested to anywhere near the amount of time required to provide a MTBF factor near even 100,000, never mind 500,000.)

To be interpreted properly, the MTBF figure is intended to be used in conjunction with the useful service life of the drive, the typical amount of time before the drive enters the period where failures due to component wear-out increase. MTBF only applies to the aggregate analysis of large numbers of drives; it says nothing about a particular unit. If the MTBF of a model is 500,000 hours and the service life is five years, this means that a drive of that type is supposed to last for five years, and that of a large group of drives operating within this timeframe, on average they will accumulate 500,000 of total run time (amongst all the drives) before the first failure of any drive. Or, you can think of it this way: if you used one of these drives and replaced it every five years with another identical one, in theory it should last 57 years before failing, on average.

I would expect a drive to last 3 to 5 years…. And so far my experience over a not insignificant number for years has demonstrated this to be a fair expectation. It is possible for a drive to fail, and having two statistically doubles that possibility. However it does not matter. The issue is that potentially any drive might fail tomorrow, and the way to mitigate against that is backup, not avoiding RAID 0 if it yields a worthwhile performance benefit that you can use.

The MTBF of the Samsung HD501LJ is 600,000 POH (Power On Hours), with a component service life of 5 years and 50,000 start/stop cycles. It is all about risk assessment and risk acceptance. Samsung make quality product, and with numbers like that, and regular backups, to me, that is an acceptable risk.

[Supershanks]

It is all about risk assessment and risk acceptance

Absolutely & avoidance ie backup/data preservation strategy

[EtheAv8r]

Howto:-
1) Ensure sata configuration is set to raid.
If new install use floppy & [f6] to load relevent raid drivers for your os (not Jmicron) Intel ones. from
Utilities, Tools and Examples - 32-bit Floppy Configuration Utility for Intel® Matrix Storage Manager (289KB)
get the correct ones for your os, xp, vista32 etc.,
2) Have windows installed on a non raid hd. (ie as Emergency XP see data drives above) , this might be your current insdtallation for example.
3) download & install Intel® Matrix Storage Manager

4) Connect drives you want to create raid on
5) Run matrix storage manager:-

You can perform the full process of adding drives & creating up to 2 raid volumes per Array.
Enable Write back Cache by right clicking on the desired volume & selecting it in the menu.
6) Switch to Windows Disk Management create your partitions & format.
7) Either install xp onto your new raid0 volume or if you have drive imaging software, take an image of your os & then restore it to the new raid0 volume(much quicker)

If you want to go yor route of doing same on your 2nd pair then play tunes on above order.

hope that helps
luck

Thank you again Supershanks

From your helpful links, I have downloaded the latest (7.5) f6-floppy drivers and Intel Storage Manager plus new chipset drivers, plus user guides on setup and confuring a Matrix RAID allowing both RAID 0 and RAID 1 as two volumes per array, and I will soon be having a go!

[Supershanks]

Your welcome Look forward to seeing the results then