Replace larger drive with smaller drive

[Schinkel]

We have a single 146GB drive (labeled disk 1 in ACU) with raid 0 fault tolerance with only 40GB of data containing the main OS of the server.

We'd like to replace it with a 72GB drive (labeled disk 6 in the ACU) so we can use the 146GB drive in another array with 146GB disks.

Mirror the drive wont work since the size is different. Cloning the disk with acronis doesn't work either: with the 146GB removed the system won't boot from the 72GB drive. With the 146GB drive replaced by the cloned 72 GB disk the ACU detects an unsupported change of slots and recognises no logical drives at all.

How could I get this done?

[MStoumba]

What OS?

[Schinkel]

The OS running on this disk is MS Server 2008

[Pieter 't Hart]

>>> with raid 0 fault tolerance <<<
raid-0 is striping amongst multiple disks with no fault-tolerance. even worse when one of the disks in a stripeset fails the whole volume fails.
either you have a raid-0 with some other disk, or you have a JBOD disk with no raid.
if it IS raid-0 then offcourse you cannot just remove a drive/ replace with different size.

with smartarray controllers you have
- arrays of disks
term raid is not yet involved here.
you can create multiple arrays with some different parameters like number of disks in an array and write-back caching.
- logical volumes
you create raid-1 and raid-5 volumes on the same array of (lets say 8) disks.
the controller selects wich physical disks from an array are used for a volume.
- a logical volume
is seen by the os as physical disk and can be partitioned to see "drives".

moving disks between slots within an array is detected by the controller with no further consequences. all volumes are accessible.
For some changes you must stay within an array or within a controller.

i expect you got the system disk on the integrated controller and the other disks on an extra controller?

so more detail about your diskconfig is needed.

[Schinkel]

It is just a single disk with no raid levels ofcourse, the controller marks it as raid 0 though. The ACU always indicates single disks always as raid 0 I believe to indicate no fault tolerance indeed.

It is attached to the integrated P410i raid controller, like the other logical disks, which are configured as raid 10 and raid 6 respectively.

I tried acronis, but that gives the problems mentioned above: replacing the original disk with a cloned disk gives an unsupported drive slot change, the controller recognises no drives at all when just the original disk (disk 1) is removed and replaced with the cloned disk (disk 6). Simply removing disk 1 and leaving disk 6 in its original place gives no errors on the controller (just have to confirm one drive was removed) but however the system won't boot from disk 6.

Still I guess it should be possible to replace it with a smaller drive, but how?

[Pieter 't Hart]

if disks are moved between slots, the controler still recognizes the disks that belong to the same array/volumes.

the smartarraycontroller write some data about the raid-configuration onto the disk.
maybe acronis really copies all disk info.
So if this info is copied from the 146 to the 74G disk offcourse there is a problem.

I'm not sure, It may be a "hidden partition"?

can you investigate and if so try to skip this partition in acronis?

the hard way is the original windows emergency recovery scenario
- make a full-backup of your system disk
including system state (onto data partition? or full backup to tape)
- replace the "defective" systemdisk
(config the 72G drive on the controller)
- fresh install windows on the 72G drive
but use a different "systemroot" !
(preferably same servicepak and patchlevel as original windows but you can also try a minimal installation)
- restore the original windows to the 72G disk (the original systemroot)
- check boot.ini and edit if neccessary
(keep two entries for both windows installations)
- boot from the original systemroot
(- you may need to restore the system state for this system root after booting from this root)
- if this works you can remove the temporary systemroot or keep it for future emergency recovery.

[Schinkel]

Thank you Pieter for your effort.

I can see a small partition on the end of the disk in Acronis (RIS tables?), however, it appears not to get copied onto the new drive.

I'm sure there must be a simple way to have the system boot from disk 6 maybe I have to edit the boot.ini on that disk....

[MStoumba]

I think this will work. Use ghost or whatever. Ghost to an image file on a IDE, sata,USB drive, anything thts not on the array. Pull the 146 gig and set it to the side. Reset the controller to default. Install 72gig drive and let the ACU configure it. Install dos on it to verify that you can boot from it. Take your image and drop it back onto the 72 gig drive from your image. That should do it.

Comments anyone?

[Pieter 't Hart]

i'm sceptic about DOS to recognize the smartarray controller.