A good time to get back...

...to the rambling buildings of Unseen University and in particular the apartments of Greyhald Spold, currently the oldest wizard on the Disc and determined to keep it that way.

He has just been extremely surprised and upset.

For the last few hours he has been very busy. He may be deaf and a little hard of thinking, but elderly wizards have very well-trained survival instincts, and they know that when a tall figure in a black robe and the latest in agricultural handtools starts looking thoughtfully at you it is time to act fast. The servants have been dismissed. The doorways have been sealed with a paste made from powdered mayflies, and protective octograms have been drawn on the windows. Rare and rather smelly oils have been poured in complex patterns on the floor, in designs which hurt the eyes and suggest the designer was drunk or from some other dimension or, possibly, both; in the very centre of the room is the eightfold octogram of Witholding, surrounded by red and green candles. And in the centre of that is a box made from wood of the curly-fern pine, which grows to a great age, and it is lined with red silk and yet more protective amulets. Because Greyhald Spold knows that Death is looking for him, and has spent many years designing an impregnable hiding place.

He has just set the complicated clockwork of the lock and shut the lid, lying back in the knowledge that here at last is the perfect defence against the most ultimate of all his enemies, although as yet he has not considered the important part that airholes must play in an enterprise of this kind.

And right beside him, very close to his ear, a voice has just said: DARK IN HERE, ISN'T IT?

Dark in here, isn't it?

Well, it has been, terribly. I thought the Pratchett piece would be a nice little intro to my return.

Sorry about the unscheduled downtime. Real life has intruded, somewhat, in the form of having to Go Out An Earn A Living.

But I am back, there's a tiny little bit of new text for you to chew over, and I am hopeful that there's going to be a lot more very soon. This will partly be due to the good offices of dougs who is going to be assisting me from now on.

So. I have rewritten the start of chapter 5, which is the one on fileservers. I've pulled out all the stuff about setting up a RAID, which I plan to banish into an appendix. Rewrite appearing here in a mo'.

This is my - and to an extent Doug's - thinking. Please feel free to demolish it.

I do tend to feel that RAID is something which should be absolutely integral to a server, though. These days there's less & less to delimit a server from a workstation; one of the few things is that servers are optimised for reliability rather than performance in desktop apps.

Now, the ideal, to my way of thinking, is a SCSI RAID setup, but frankly, if you're a small business & you can afford that, then you can afford Win2003 Small Business Server and a bunch of CALs. Let's face it, you're probably building your own server 'cos you haven't got loads of spare IT budget, yes? Does this seem reasonable?

So there are 2 alternatives.

IDE RAID or software RAID.

Pertaining to IDE RAID, I would instantly rule out those nasty firmware RAID cards - the sort of £20 things you get in Maplin's. These don't do real RAID, all they do is implement a driver which lies to the OS that a mirror pair or a stripe is actually a single disk. The main reason being that workstation versions of Windows can do striping but they can't do mirroring or true RAID, level 5 or higher.

These things are, from what I have read, a swine to get working under Linux, arrays are not very portable between devices, performance is not great, and basically, you might as well use S/W RAID instead.

I have a server here running Linux S/W RAID and it's pretty good.

One question is:

Are there any cheap good IDE RAID cards out there yet which do real RAID, as in, the host adapter controls the RAID entirely on its own, with no OS involvement? I have a couple of clients with Dell servers with CERC (rebadged ALI MegaRAID) cards in, but those, even at Dell's heavily-subsidized prices, add £150 to the cost of your server. This probably translates to 2 or 3 hundred quid in the real world. I.e., /considerably/ more than the cost of the disks.

That may be too expensive for my target readers.

I don't know of any true H/W IDE RAID controllers that cost down around the price of a disk - which means sub-£100, really. Am I out of date on this?

So, if H/W RAID is out of the picture, I'd like to advise people to use S/W RAID as an alternative and monitor it /zealously./

Comments?

- - - - -

I also have a germinal intro to the chapter on LAMP servers somewhere, if I can find it. That might also follow soon. Little real content there, though.

More on H/W ATA RAID

I've been having a quick look through Froogle.

It looks like there are some reasonably affordable ATA RAID cards now...

http://froogle.google.co.uk/froogle?q=ide+raid+adaptor+card+-workstation+-tower+-barebone&btnG=Search&hl=en&show=dd&scoring=pd

Highpoint seem to do a range. IME - which is fairly limited, TBH - one of the distinguishing features of a "true" RAID controller is RAID5 support. If it only does 0/1/0+1, it's a firmware controller; if it does 5, it's probably the real deal. Agreed?

Anyone got any personal experience of these Highpoint controllers?

Everything <£50 looks to me like a firmware job... But there's at least 1 £75 card which looks to me like the genuine item:

http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=83203&source=froogle