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[xen-uno]

Just bought (2) 60 GB EIDE WD hard drives so...

Any hands-on experience with the subject before I proceed tomorrow? (or on any from the NT family). I plan on using W2k's software RAID.

I'm wondering if I'm going to dislike the performance of this "mini-RAID" using the MoBo's IDE controller versus a dedicated card. I've set up a striped array using two SCSI drives and it worked out nice (used NT's software RAID). Not really true RAID since I didn't set up a 3rd drive for parity checking. In this setup, if I lose a drive, I lose the data (but it's faster than either drive alone). I want to go with mirroring this time for data redundancy.

10^-27

[KingSparta]

I would also like to know more about it.

Like if one goes bad does it tell you?

how do you recover data from the good one if the second is bad?

if you replace the bad one, can you replace it then copy the good drive to the second and new drive?

[xen-uno]

King..

> Like if one goes bad does it tell you?

System should start displaying error messages and the event log will start filling up with read/write error entries.

> how do you recover data from the good one if the second is bad?

Since they're mirrored, they are perfect replicas of each other. When a drive fails, you replace it, then re-establish the mirror. Contents are copied over from good drive to the new drive...or something to that effect. I haven't personally experienced an actual crash in a mirrored situation....so I guess I'm suggesting what should happen.

10^-27

[xen-uno]

King..

Just so we're on the same page, here is Mirrored Volume defined (from W2k Help file)

"A fault-tolerant volume that duplicates data on two physical disks. It provides data redundancy by using a copy (mirror) of the volume to duplicate the information contained on the volume. The mirror is always located on a different disk. If one of the physical disks fails, the data on the failed disk becomes unavailable, but the system continues to operate using the unaffected disk. A mirrored volume is slower than a RAID-5 volume in read operations but faster in write operations. You can create mirrored volumes only on dynamic disks. In Windows NT 4.0, a mirrored volume was known as a mirror set."

RAID-5 is striping data across 3 or more disks

I think I'll just try it on this machine. I'll let you know.

10^-27

edit > As you can see, no mention is made of system impact by writing to 2 disks concurrently on non-dedicated hardware.

[Matthias]

The software overhead is about the same as a Promise RAID card, if I recall correctly.  Also, if one of the drives fail, nothing stops.  A look at the Disk Management will just show that the mirror is no longer functional, and will show one of the drives as missing.

Hardware is always better, IMO, for a few minor reasons, BUT, I've found that Promise cards leave something to be desired, at least for business use.  At least on their lower-end Fasttrak stuff....which is why I use the conversion techniques to upgrade the Ultras' to Fasttraks.  I just don't find the regular Fasttraks worth the $$.  As for some of the other IDE RAID companies, like the ones that come onboard with a lot of motherboards...well, their drivers suck, IMO.

~Matthias

[xen-uno]

~Matthias > The software overhead is about the same as a Promise RAID card

"software overhead" as in the RAID that comes with W2k (or NT or XP)? Forgive me, I'm sure that's what you meant.

10^-27

[Matthias]

That is, the over-all CPU usage is the same when you compare the mirroring of NT's software vs. Promise's cards.   A better place to double-check this would be storagereview.com

~Matthias

~Matthias > The software overhead is about the same as a Promise RAID card

"software overhead" as in the RAID that comes with W2k (or NT or XP)? Forgive me, I'm sure that's what you meant.

10^-27

[Robert Taylor]

I'm using an MSI motherboard which has a  Promise Fastrak Lite RAID controller onboard. I have twin Seagate Barracuda 80Gb drives connected.

It is limited in that it only supports striping (aggregates both drives for around 160Gb, but no security of data), and mirroring (I only get 80Gb capacity, but if ONE (and only one) drive fails, I don't lose my data)

I have found this drive performs very well as a repository for MP3s, especially as they are streamed across to another machine connected to my loungeroom stereo system, so I don't think performance is a major issue here.

I have already filled my 80Gb mirror, so my next plan is to buy a full-blown Promise PCI RAID controller, which will allow full RAID (ie. then I can buy one or more drives to add to my existing two, and create a RAID 5 array, where the data is striped across the disks, but it includes parity info so that the data can be rebuilt in the event of any drive failure)

I don't think should really be an issue here. I mean if you used the built in RAID controller drives to house a hard-hit database, you might notice it, but not for storage of (fairly) static stuff like a bunch of MP3s.

Hope this helps...

[Jaguu]

Hi xen-uno,

I bought a new PC two weeks ago, which also has an MSI motherboard with a  Promise Fastrak Lite RAID controller onboard. I mirrorered two 80GB disks which is enough for me. It has two other non-mirrorered  40GB disk attached to the standard EIDE controller with the WinXP OS and all software running , so that I have 160GB of space altogether. All my data (docs, music, images) is on the mirrorered disks. Should my PC break, I can take out one of the mirrorered disk and insert it on another PC.

By the way: software mirroring with W2K is very tricky: it was introduced with NT4 and taken out of W2K and WXP for who knows which reason. If you make a fresh install of W2K/WXP, there is no soft mirroring any longer, unless you will be using the server version.

But if you do an in-place upgrade of NT4 workstation to W2K and you have soft-mirrored disks, the mirroring is kept until it breaks once. So after your first disk failure your mirroring is gone for ever.

So you better forget about soft mirroring on W2K unless you will do it on a server. But it is probably better to go with hardware mirroring.

[xen-uno]

Jaguu..

Your absolutely right (from the help file)...

"You can create mirrored volumes only on computers running Windows 2000 Server"

So what have people paid for a add-on IDE RAID card?

10^-27

[Jaguu]

I bought an MSI KT3 Ultra2-R (R for Raid) mainboard for about 120U$ here in Switzerland. The standard mainboard MSI KT3 Ultra2 was only 20U$ less.
It has an ATA 133 Raid Controller on-board from Promise with two ATA 133 Raid connectors. So you can attach a total of 6 hard disks to the 2 controllers, 2 disks to the standard EIDE controller (+ CD-ROM/DVD) and maximum 4 disks to the Raid controller that can be either striped or mirrored.

My pc's  run with an AMD Athlon XP 2100+ processor and 512MB memory.

Bear in mind that mirroring helps only in case of disk failures. If you mess up your files on the disk, then they are messed up on both disks!