RAID Server, logical drives/partitions

The RAID controller must be used to define the logical drive in a RAID5 array. Once you create a RAID5 array from your 3 drives, it will be seen as one logical drive by the OS. In RAID1, if you're using hardware RAID, again once you create the mirror, the two physical drives will be seen as one logical drive by the OS. If you use software RAID for the mirror (through Disk Administrator), then the OS will see both drives individually as physical drives, but will allow you to bind them togetherin a mirrored configuration and will show them as being part of a mirror. In either case, you can then create different partitions and/or volumes using the NT operating system (Disk Administrator) just as you would with any other type of drive. Hope this helps!

Let the RAID card that was designed with one purpose, perform that function. Recovery from a failed disk is MUCH easier at the controller level. You replace the disk and let the controller rebuild the array. Windows never knows what happened.

There is a series of steps you go through when a disk fails under Windows RAID. Rebuilding an array is pretty intense, more so if the OS also does its normal functions. Let Microsoft be an operating system. They are pretty good at that.

You paid for a RAID controller. Use it.

Hi Synergy,
I know all details about RAID and OS that you described. But in case of failure (HDD, OS, RAID) which one of these partition configurations(RAID, OS, mixed) can be easy restored or offer an easy management/maintenance/etc.

At the RAID level you have a utility that configures your raid card to whatever you want your disk config to be. So if you set it up as you want, that is what it will be. So far as the O/S, it will only see one drive. That's the purpose of the RAID card-to transparently present the array as a single disk to the O/S.

It should not matter. Once you create the partition, it is essentially hard-coded on the disk.

The only possible issues are whether the RAID utility offers the option of creating partitions and whether the OS recognizes them. I wouldn't think this would be an issue unless you have an extremely old RAID controller.

A possible issue arises with NT4 if you will be loading it from scratch. Since NT4 initially formats the system/boot partition as FAT, it is limited in size to 4GB.

Personally, I would do any partitioning using the NT4 Disk manager solely from the standa point of being able to manipulate partitions after the OS has booted.

Tim,
I install this server from scratch. I have a server guide CD which I used to boot the server. After that, it show up a RAID manager utility where I can define the arrays and if I want in these arrays I can define logical drives. Also the maximum size for system partition is 4Gb.
I think that Greybeard have right when say to let the RAID to do all it can do (I can use this Guide CD to change the partitions/logical drives after the OS was installed or I can install this RAID manager in WinNT).

It DOES matter if you use hardware or OS RAID.
Using the OS to maintain your RAID array will slow the system down. Also, in the event of a crash you might never be able to recover your operating system's hard drive data. This is why you should use hardware RAID anytime you can afford it.
I have actually had to use Microsoft's DiskProb, DiskSave and FTEdit to recover data from software RAIDed hard drives. Checkout Microsoft's WinNT Server Resource Guide, chapters 4 through 7 for an idea of the trouble you have to go through to recover one of their software RAIDed drives. Believe me, it is much better and faster to rely upon backups rather than try to recover from an OS crash on software RAIDed drives.
Do youself a favor and use your hardware RAID solution. And don't forget those backups.

Make a sound decision!
ralph

Greybeard,
If I must need to change the RAID controller (in case of failure) how the new controller will recognize the existing arrays or logical drives?

As already stated, when you define the arrays they are presented to the OS as if they were seperate new HDs. The RAID controler or it's management software have to do this, not the OS. The same should be said for the logical drives. If your RAID management software supports creating the PARTITIONS I would use it over the NT/2K disk manager. I think Dells do this. The NT disk manager would probably work but the RAID software should have a more exact match for commands being sent to the hardware. Another thing to pay attention to is if your RAID controler supports adding drives later, it will often spread the new space among the logical drives and you should size accordingly. Maybe that answers your question on whether to use one logical and let the OS partition or use multiple logicals. Depending on your RAID sft multiple logicals might be more reliable than depending on the OS to keep track of partitions. More chance of corruption.

Hi Florinel,
For my ten cents worth, I would go with using the RAID Controller to mirror image two drives for the O/S and then have the O/S handle the RAID5 on the other 3. Reason for this is that in the event of any single HDD failure there is a system in place to automatically rebuild the drives (as far as you can call it automatic I suppose) and if the controller fails, then trust in those backup tapes.

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