Can't set up raid 5 on HP server

Perhaps this will help you out? http://support.microsoft.com/kb/323434

Jeff
TechSoEasy

So, it sounds like when it says that you need three disks in order to make a RAID 5, it means three disks over and above Disk 0 where the operating system resides. I only have a Disk 0, 1, and 2. So, maybe only two disks are available for RAID 5, which would not be enough.

Please advise.

Thanks.

Bert

Does your server have a RAID controller?  If so, then you can and should use the configuration software for the hardware RAID to create your volume prior to installing SBS.  Otherwise, as the KB article points out, you cannot create a RAID5 with Windows unless it is separate from the OS and boot files.

Jeff
TechSoEasy

So, I could go back and do that. If the SBS is already installed and you must use three separated disks (from what I understand) to have a RAID 5 separate from the OS, is there an advantage to that. In other words, is having four disks with three used for raid 5 in the end better than using three disks with the raid being set up prior to the install?

 

Essentially, yes.  If you keep your OS separate from your data, it's always better.  If you can add another drive to the server, I'd go that route... since 160GB SATA drives are less than $100 these days.

Jeff
TechSoEasy

Plus... then you'll get 320GB of storage space if you do it that way.

Jeff
TechSoEasy

So, I am a little confused. I have three 160GB drives. One is for the server and data, etc. The other two for the raid. That would give me 360GBs of storage space. Or do I have to use another 160GB drive for parity?

Thanks. It's all new to me.

If you currently have three 160GB drives... one is for the server... NOT data.  

Data goes on your RAID5
So you would add an additional 160GB drive to create your RAID5 with three drives.  A RAID 5 with 3 drives will result in 2/3 the total amount of space because as you stated... one is used for parity.

Jeff
TechSoEasy

Thanks. So, if you use the first drive (of the four -- if you add one) for just the OS, isn't that a very large drive for the OS? Or can the OS drive be smaller than the three RAID 5 drives?

If all of one's data is on the RAID 5, when you do backups; do you simply back up the three raid 5 drives or would you back up the OS as well?

I guess I could set up a mirror, but then I would have an extra drive. Do you prefer a mirror setup or RAID 5 or RAID 10?

Thanks.

It is large for the OS, so I'd create a 25GB partition on it for that... and use the rest for things you don't need to back up... for instance, I'd put all of the original install CD's on there so you don't have to pull them out when you need to make an OS change.

Jeff
TechSoEasy

What about simply using the three existing hard drives for the RAID 5 and then adding a 40GB drive for the OS? Or does even the OS drive have to be the same size as the other three?

I guess I could remove a drive and mirror the other two and then have a good drive around if I needed to replace one?

I guess this begs the question of is a RAID 1 better than a RAID 5. How do you do the backups in a RAID 5? Do you simply back up all of the three RAID 5 drives? Do you back up the OS?

Sorry, again, very new to this?

Thanks. By the way, is it possible to have a RAID 5 while using another hard drive to mirror the OS disk?

Thanks for all the help.

Bert

You can... but it's really not necessary, since the process of breaking the mirror and replacing a new drive would probably be more complicated than just restoring from backup.

See http://en.wikipedia.org/wiki/Raid_array for a good overview on RAIDs

Jeff
TechSoEasy