Two Arrays, One Set Of Disks

[SgtJarrow]

We have recently decided to upgrade one of our servers from 9G drives to something bigger to increase space. We have two 18G drive available and I was wondering...

I want to swap one 9G with an 18G and let it rebuild...
I want to swap a second 9G with the second 18G and let it rebuild
I then want to put in one of the old 9G and build a new 9G array of of this and left over space from the two 18G.

So end result:
9G #1, 18G #1, 18G #2
9G #2, 18G #1, 18G #2

Is it even possible? My boss seems to think it might be, but I don't. I am pretty sure I could create a software based array for the second array, but I don't know about two hardware based arrays with the same set of disks. Thanks in advanced.

****************************
When the human body encounters disease it raises its temperature making it uncomfortable not only for the body but also for the disease. So it global warming the Earth's way of saying we are not wanted?

Robert L. Johnson III
MCSA, CNA, Net+, A+
w: rljohnso@stewart.com
h: wildmage@tampabay.rr.com

 

[terry712]

not sure i fully understand your table
you currently have 2 * 9gb drives in server? raid 1 hardware i assume - you want to take first disk out and put 18 gb drive in - after rebuild do same to disk so now you have 2 * 18 gb drives but each one with 9gb free space
you then want to add one of the nines in and make a raid 5 with the 9gb's on each drive giving you another 18gb raid 5?

this hardware raid wise not possible - as you can allocate a drive to more than one hardware array. software wise you could as it would see the 3 sections of empty space but i'm a firm beleiver that software raid is suicide.

 

[SgtJarrow]

terry712,

sorry for the confusion. first, yes I agree that software raid is carzy and would never do it...especially on a sever. second, my setup is as follows:

three 9G drives, RAID 5
wanted two arrays 9G RAID 5 arrays using two existing 9G drivers and two 18G drives

afte rsome more research, I think I have discovered it is just not possible. just like I thought, but I was looking for another opinion to tell my boss we can't do it....

thanks

****************************
Computers are possibly the most un-intelligent things ever invented, yet we let them control the world. Possibly a reflection of our own stupidity.

Robert L. Johnson III
MCSA, CNA, Net+, A+
w: rljohnso@stewart.com
h: wildmage@tampabay.rr.com

 

[terry712]

only real option is to slap the 2 18gb's in as a mirror pair and leave the 9's alone - but that's limiting in the future

or get another 18 gb and replace the 3 drives

 

[SgtJarrow]

yep....when I told the boss the only option was to buy a third 18..he was okay with that...should have it early next week and everyones happy. thanks again.

****************************
Computers are possibly the most un-intelligent things ever invented, yet we let them control the world. Possibly a reflection of our own stupidity.

Robert L. Johnson III
MCSA, CNA, Net+, A+
w: rljohnso@stewart.com
h: wildmage@tampabay.rr.com

 

[Trackhappy]

Strange concept, but I have been told it can be done on some controllers. Haven't got enough drives to try it unfortunately. Plenty of servers at present though .
If I can wangle some I'll post the results.

 

[terry712]

i could try it
have the servers and the drives but cant see how it would work

surely a physical drive can only exist in one array.

if it does work then the recovery scenario's of a failed disk would be a nightmare