I have an in-law who works for a small company. They currently have an old NT4 server and are looking at upgrading to a new machine. I'm looking into options for them and have a question or two.

They have around 10-12 PC's that connect to the server, all Windows flavors from Windows 98 and up. The server is used for printing, file sharing and a tiny bit of application sharing (Peachtree Accounting and maybe one or two other things). There are only, as noted, 10-12 user's so only that many user accounts on the current server as well. The old server is a Pentium 2 or 3, 450 MHz, 512MB RAM, 10 gig hard drive, etc. It is obviously old and ready for replacement. Altogether what they have is a very simple setup and should be easy to replace with something much more robust yet inexpensive.

They currently have no form of RAID in use. Most of the servers I'm looking at offer that for fault tolerance. I don't know much about RAID, so which version is best? RAID 1 or RAID 5, especially considering what they have now and how small a shop they are. Also, I'm assuming (I think it's logical) that if RAID is used the server will need a RAID controller. Again, forgive me for my lack of knowledge on the subject.

My thinking is that RAID 1 would be more than sufficient for these people. They have lived without it for so long that any form of fault tolerance will be a boon to them. Any server they get and setup will be an improvement over what they have, even without fault tolerance. What do you all think? Any help would be great. Thanks.

RAID 1 and RAID 5 are very different. I use RAID 5 (with 5 HDDs). basically any of the drives can fail and the system will not go down. you remove (hot swap) the faulty drive and plug in a new one. the system auto rebuilds the data on the new drive. For this you need a special raid controler and hardware (the server box or external housing for the drives. RAID 1 can be done on some pc's nowdays using 2 internal drives and the onboard EIDE controller. The master drive is mirrored to the second. (The second drive should not be visible to normal apps.) If the master fails you must power down and swap second drive to master and install a new secondary drive.

There are also all sorts of RAID add-on cards available - e.g. ADAPTEC

Manxmania, thanks for the reply. With RAID 1 do you have to "break the mirror" in Windows or something like I remember reading about years ago (under NT 4.0 I think) before swapping the drives should one go bad? Also, you mention that the second drive can't be used for anything about the mirroring. Is that right? So I'd have two drives but only be using one actively while the other is being used as a mirror of the first?

RAID arrays can be done in two main ways with Windows. You can either...

A. Use an actual RAID controller such as a Promise FastTrack series.

B. Set a raid array up using technology built within Windows.

Usually controllers work best and are recommended since they don't really cost much and offer much better performance usually.

RAID arrays can offer fault tolerance and/or increased disk throughput. RAID0 is a stripe that offers more throughput, but at the cost of increased risk of data loss and availability. This is because the data blocks are written on alternating hard drives. In effect, if one drive fails, half of EACH file goes with it, making the other halves worthless. The drives are then combined for storage, so 2 x 80 gig drives yields 160 gig of storage in RAID0.

RAID1 is a mirror. All data on one hard drive is cloned to the other. Therefore, if you have say two 80 gig drives, you still only have 80 gigs of storage. This gives minimal speed increases, but reduces risk of data loss and increases reliability since if one drive goes down, the other kicks right on in. Do remember RAID0 does nothing for protection against data loss through user error or virus attacks, etc. It only provides additional protection due to hard disk physical failures.

RAID5 is a sort of combination of the two. It's a compromise of striping (RAID0) for performance and mirroring (RAID1) for fault tolerance.

http://www.pcguide.com/ref/hdd/perf/raid/levels/singleLevel5-c.html

You can see in the article it's not as wasteful in storage as mirroring is, but doesn't give the near 100% of useful storage space that RAID0 does. It also offers some of the advantages of striping, so speed would be increased. The big knock on RAID5 is the increased costs associated with a better RAID controller that supports it, and the minimal number of hard drives needed (3 opposed to two in RAID0 or 1).

Do keep in mind what RAID1 or 5 offers before you plop down the money for it. Remember it is only effective for disaster recovery due to a physical hard drive failure, and only when the failure is the result of the hard drive itself, not if say your power supply causes the hard drive to fail (since the power supply would need to be replaced). On top of that, it's biggest real advantage in that the array fails over automagically to the good drive(s), allowing for no loss of availability except for when the bad drive can be replaced at a convenient time. Everyone wants near 100% availability, but if RAID were so beneficial, we'd all be running it. ;-)

Get down to real facts about what is the realistic goal of the company as far as availability and budget goes. Maybe the business doesn't need that kind of availability, especially considering it's no guarantee against loss of data or availability by other means.

MCSE, MCSA Messaging, baby!

Considering the size of the company and number of users I would suggest (and it's only my experienced opinion) that you go with RAID 1 on a server type computer not a high end workstation. They are two completely different animals. Servers with built in RAID controllers are very common and very reasonable. You will have hard drive mirroring at the hardware level so theirs nothing that will tax the operating system. What you will pay the most for are the drives and CPU's. RAID 1 will be the easiest to recover from, for the money, if their is a problem .