Increase the size of a raid 1 array

I have an IBM server with a IBM ServeRAID 8K-I raid controller.  It has a RAID 1 array on it with 2 SAS 300gb HDDs.  The mirror is split into a c partition and a d partition.  I am running out of space.  I have purchased 2 SAS 600gb drives and need to determine the easiest way to get them installed.

I thought I could replace them one at a time and let the mirror rebuild itself each time but I am not sure how to resize the partitions.  The other option is I could put both new SAS drives in, create my mirror, then use my most recent acronis image to restore.

any advice would be greatly appreciated.
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If you've got Acronis,you should just be able to insert the new 600gb drive and just use the clone feature

You should be able to adjust the partition sizes on the fly.

Should be pretty straight forward..
Create another RAID1.  

Then move the "D" disk there & expand "C".

Then also put the swap on the new D drive.
.  If you go to a RAID10 array then your I/O model will change as you will have to deal with stripe size.  While sequential throughput will increase, transactional IOPs will decrease.

Set NTFS to 64KB chunk size on the 2nd RAID1.  That is the native I/O size of SQL server, and it is most efficient.   Then shut down databases and start moving the data to the 2nd RAID1 as it will be more efficient there.
All sorts of freebie partitioning tools in linux if you go to and download a distribution you can boot from a USB drive.  (Instructions on the home page).

Or go to a PC store or office supply store that has Pc software and get some partitioning software that works with windows if you aren't comfortable with linux.
dlethe has given excellent advice and should be listened to!

The only thing I would add is I have had good experience with EASEUS partitioning software (even the free one)...

It is available here:

If this is a one-shot deal, the free version may suffice...
If you will be doing this on a regular basis, you might consider one of the paid versions!
To add, if Windows 2003 then you can align the new D: drive. Not as important with RAID 1 as with RAID 5 but still worth doing, we don't know what OS you have yet but you may be able to expand C: without 3rd party tools if it is Win 2008.
GrolffAuthor Commented:
its windows 2003 standard sp2.  my c: partition is fine, just need to make my d partition bigger.

little confused about dlethe's comments.

"Create another RAID1"  - Ok stick the new disks in and create an array.

"Then move the "D" disk there & expand "C"." - Use acronis to restore from my image?  expand D not C i believe, using some third party software?

I dont have raid 10 so I dont need to worry about this last part I believe.

my block size is set to the default 4096.  should i change this?  how can i change it?
Make the 2 new disks, call it D.   Copy partition currently in D to the new drive, and resize to the entire disk.   C is unchanged.   D is 300GB

Then you can now use E:\ to replace the area previously in C:, or resize C, whichever you prefer.

You open up a big can of worms by creating a 4-disk RAID10, starting with risk of having to blow away all your data and O/S and restore from a backup to start.

If 300GB isn't big enough for D, then either use the new E space for some of that, or go with a RAID10 and create a full backup, destroy and rebuild an empty RAID10 using 4 disks, or go with a 4-disk RAID5, and suffer the performance hit.
The Block size is set when you do the windows formatting on the partition you carve out of a disk drive.

It is the dropdown above where you tell it how many GB you want the partition to be.  You can't resize C on-the-fly. (You probably wouldn't want to anyway).
GrolffAuthor Commented:
If Acronis will allow me to resize the partitions on deploy then that should be the simplest.
unless they recently added it, acronis won't let you set the NTFS allocation size.
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