Adding HDD to Smart Array 641

[Adrian Ionut]

Hello all,
Well, I'm new here, but I think the forum is the best place to find a good answer.
I have an HP Proliant Server with an SCSI controller (Smart Array 641). The array is already configured as RAID-5 using 3 72GB HDD.
The problem is the space on server is becoming lower and we need more space. The company has decided to buy another HDD - this time an 146GB SCSI.
So far so good, but my problem is how to configure the new HDD? Is it posible to just add it as an single HDD, without affecting the existing RAID-5? It is vital not to destroy the existing RAID! I tried to install it as an sigle drive, but I'm afraid I don't know the right procedure and if I remember exactly I had an message teling about affecting all others RAID as well. When I try to do dat, the only option I have for the new HDD is RAID 0 (?) but I know for sure that is not RAID (you cannot create any RAID structure with only one HDD).
Another solution might be to extend the existing RAID-5 (form what I've read) but I will loose some space - at least half, I suppose. It is possible to extend the existing RAID without loosing any data?
Thanks in advance,
Adrian.

[gregersenj]

Yes

You can add the new drive and create a new array and create a RAID 0, with 1 disk only.

Or you can add the new disk to you existing array, and even extend the LUN (If yoy operating system can handle it)
This will leave you with 74 GB unused.
You can then create a RAID 0 on the remaining space.

You can have multible LUN's on the same array, with different RAID Levels

And RAID 0 can be created on 1 disk.

You can do it on-line, using the ACU (Array Configuration Utility)

Remember to get a good backup, and disaster recovery plan.

BR
jag

[Adrian Ionut]

Hello,

Thanks a lot for your answer. The OS we are using is SBS2003 with SP1 and we have an good backup. What is an LUN? Sorry for the silly question, but I'm kinda newbie...

[Steven Clementi]

a LUN has several meanings...

The ones appropiate here would be...

a logical representation of storage addressable on pyhsical hardware.

and

Logical Unit Number

and

a subunit of a disk or set of disks.


I.E.:

2 72GB drives on a SMART array can be configured as a Mirrored pair or have no redundancy at all.

total space available would be..

72GB RAID1
144GB RAID0

Out of that space, yo ucan create "subunits".

25GB for your OS or your "C" drive = LUN 1
47GB for your data or your "D" drive = LUN 2


The first thing we need to know is what is the model of the server?

The second thing is... is your Data in a separate LUN? or is it in a separate partition?

You can figure thous out by looking at the disk administrator. If you have 1 drive with several partitions on it, then it is 1 LUN.

If you have multiple drives, 1 for your C: drive, 1 for your Data drive, etc... then it will be easiere to extend the existing configuration.


"...RAID 0 (?) but I know for sure that is not RAID (you cannot create any RAID structure with only one HDD).
"

Theoretically yes, you are right since how can you have a redundant array of "diskS" with only 1 disk.

But the way the Smart Array works is a little different. Even with only 1 drive, you still get RAID0 option since RAID) does not involve any redundancy. Just full allocation of available raw space.



Steven

[Adrian Ionut]

Hello Steven,

"The first thing we need to know is what is the model of the server?"
I have an ProLiant ML350 G4.

"...is your Data in a separate LUN? or is it in a separate partition?"

Well... the ACU is telling me that I have 1 logical unit with the size of 138919 RAID-5, so I think I have 1 LUN, with 4 partition on it.
What to do next? Like I said before, the only thing I need is some extra space. I don't need redundancy (even if it sound... odd). So it is OK to create an RAID 0 with the new disk? My bigest fear is to not destroy the existing RAID-5.
Thanks,

[Steven Clementi]

Ok, so you have a couple of options...

1a. insert the new drive into an available bay.
1b. add drive to existing array
1c. you now have additional space to either create a new logical drive or expand your existing logical drive.

The only downside to expanding your existing logical drive is that you will not be able to use the extra space in your C: partition. It is likely that you would only be able to use it in the last partition on the drive, though I would have to do some testing to see if it could be used on any of the other partitions.

or

2a. Insert the new drive into an available bay
2b. Create a new array with the 1 disk.
2c. Create a new logical drive, RAID0.. 146GB

If you go with option 1, you will only be able to use 73GB of the 146GB drive. Potentially can be troublesome with your existing array

If you go with option 2, you will have use of ALL the space on the drive. "Should" not even touch your existing array or cause problems.


Steven

[Adrian Ionut]

Hello,

I think (actually I'm pretty sure ) I'll go with the second option.
I will try it friday. Is firmware update necessary (for the smart array controller)?
Thanks again for your very clear answer.
I'll be back with (hope) good news.

[Roger Rios]

For create this new array...the server could be reboot and use SmartStart HP or not?

[gregersenj]

>Rios
You don't have to reboot, you can do it on-line.

I you want, you can do it offline, but that won't be more safe than doing it on-line.
It will just caurse some downtime.

Off-line you got 2 tools:
ORCA (F8) - Simple.
Or ACU from the Smart Start - Advanced.

On-line, you got the ACU.
I can't remember if you can run from the Smart Start CD, if you haven't installed it.
If not you can install ACU from the Samrt Start CD og the PSP.

I do it on-line.

[Roger Rios]

Hi gregersenj,
i have issue, actually there is an array with two hard disk 36.4 smart array 6i controller(1 logical drive), the server is DL580 G3 and buy two disk 146.8 GB...how can I create an array for these two additional hard disk from the ACU?