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Expand Disk Array w/ Larger Disks ACU Elegant Solution

 
Kirk Watson
Occasional Advisor

Expand Disk Array w/ Larger Disks ACU Elegant Solution

A problem faced by many in the Small Business environment, typically running SBS. Buying whole addtiional servers to migrate is not an option, etc.
Background: Server w RAID card (here, DL 180G5 with E200 and BBWC) with three smaller SAS disks (here, 146). Suddenly need much larger storage, and would like to migrate away from the smaller disk to maximize the total storage available internal to the server without an MSA.

What is the best way to migrate?

I have seen a solution of adding the larger drive, pulling out the smaller and letting the system rebuild, and repeat one by one, until all teh smaller drives are out one expands the array with disk management in SBS2008. I have read some concerns regarding RAID 5 stability in this case.

The other is with imaging software... Symantec System Recovery has a copy disk (including functions to copy the MBR and to set active). But on failure, how does on reset the original three drives to be the boot drive?

What is the easiest solution? Safest? What is the HP recommended solution? Is there a white paper on this?

Thanks
9 REPLIES 9
Michael A. McKenney
Respected Contributor

Re: Expand Disk Array w/ Larger Disks ACU Elegant Solution

Replacing each disk in fail over mode is risky. You could add an MSA storage unit or SAN or a NAS. Then attach the server to it.

Is this your only active directory server? If yes, I would consider buying a second server and migrating applications to it. You should have two active directory servers and a member server for your applications/data.

RAID 5 is not recommended for your OS or paging file. It can corrupt your registry and cause OS to fail. You should use RAID 1 or 10 for OS and paging.

I would start by determining how much storage space you will need over 3 years. Can you archive off data to CD/DVD or tapes?

Easiest is not a good way of doing it. I would look at the best practice and safest method. You should consider a new server with RAID 1 for OS and paging. Look at a hardware based NAS solution. Get a good backup solution that you can take offsite like tapes or a Barracuda cloud device.




Johan Guldmyr
Honored Contributor

Re: Expand Disk Array w/ Larger Disks ACU Elegant Solution

HP has a white paper here about breaking a mirroring RAID.

http://h18004.www1.hp.com/products/servers/technology/whitepapers/proliant-storage.html#array

Maybe that can be of some assistance.
Kirk Watson
Occasional Advisor

Re: Expand Disk Array w/ Larger Disks ACU Elegant Solution

Michael,

You're obviously a very technical guy. However, this is a small business environment, so the law of number states that there are more SBS installations with 5 clients than 75 clients, and therefore, with not large IT budgets. So, yes this is the only 'active directory' and no, there isn't the money for a second server (nor the time or money for its care and feeding.) Regarding RAID 5 it is a common installation for a single RAID 5 in an SBS environment, and it seems to be supported for SBS given this link: http://technet.microsoft.com/en-us/library/cc527594(WS.10).aspx Furhter, there is space of 4 drives, but not another storage controller, as the E200 supports only internal drives and there ins't space for another RAID controller in the smallish DL 180 series. The site DOES have offsite storage with LTO4 tapes and a 1Tb US RDX device.. it is simply the requirement to max out what is available in terrms of space on the server today.

Thanks for your response.
Johan Guldmyr
Honored Contributor

Re: Expand Disk Array w/ Larger Disks ACU Elegant Solution

One big concern with doing it like this is that your array is quite vulnerable while it's doing the rebuild - and the rebuild takes quite some time.

Something I would recommend you to look into is to make a backup, erase the array, upgrade the drives, create new/bigger array and then put data back on from backup.
Kirk Watson
Occasional Advisor

Re: Expand Disk Array w/ Larger Disks ACU Elegant Solution

Agreed about the copy and reinstall. I think Symantec System Recovery (SSR)can do it... One could build a new logical volume, copy it and make it active, all supported by SSR (used to be BESR) What I would REALLY like is (even after a tape or USB backup) to be able to go back the the original logical volumne and be able to boot from that logical drive.(one woudl have to be caredul here about which image one is using.. but quiexicng services would help in that regard). Evidenlty ORCA (as opposed to ACU) lets one stipulate the bootable controller.. but is there a way to specifiy the logical drive to boot with two logical drives on a controller? I have looked and can't find antyhing. Now that would be the ticket. I will build a new logical drive an reboot to take a look at the controller microcode to see if it is in there. I just reflashed all the code, just to be safe and to get the latest functionalilty.

I took the link you mentioned above, and will read the WP. Looks very promising. I hadn't found it in my searches. Thanks
Michael A. McKenney
Respected Contributor

Re: Expand Disk Array w/ Larger Disks ACU Elegant Solution

I have built networks since 1982. I used to build for 5-7 users. Two AD servers and a member server is a good solution. You are looking for a safe solution that is the best practice. How much is one day or one week of downtime cost you?

A NAS is a network attached storage device. They have 1Gbps connections that go on your switch. You put your applications on it. Two Active Directory servers protects your network from failure. If you lose the AD server, you are in trouble.

I am not a fan of a NAS because they are not great solutions. A SAN is better. A NAS is a poor man's SAN. LaCie has a decent NAS that would solve your problem. $1000-$1500. You move your data to the NAS.
Kirk Watson
Occasional Advisor

Re: Expand Disk Array w/ Larger Disks ACU Elegant Solution

Mr. McKenny.

I appreciate your concerns regarding multiple machines and respect your experience. I too have experience as an IBM SE for 13 years in midrage systems, then Unix. The guys selling water cooled machines to United Airlines don't get a small company with 5 people. It's just different... one thing being the size of the pile of money involved. And in small companies today, a grand is a lot of coin.

The issue is to move the bootable RAID configuration. One COULD also move this to a mirrored RAID as you propose, and that is a good idea for residnece devices. The trick is how to do it on a low functionality RAID controller such as the E200...
gregersenj
Honored Contributor

Re: Expand Disk Array w/ Larger Disks ACU Elegant Solution

Replacing disks 1 by 1, does have a risk.
Same as if you have to replace a defective drive.

You can minimize the risk.

Check that all drives is error free
Use the System management homepage, that's the best/easiest tool for that purpose.

Ensure you have a good, testet backup and disaster recovery plan.

Why do you consider the e200 to be a low functionality controller?

http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00687518/c00687518.pdf


Alternative solution:
Install a 4th large drive. Bigger than the current logical drive.
Create a new RAID 0, on that drive.
Create a software RAID 1
Create a bootable USb mem stick. Copy ntdect, ntloader and boot.ini to the pen.
Chenge the boot.ini to boot from disk 1 (That would be the mirror)
Test that you can boot on the mirror, using the usb memory.
Now you have a full functional copy.

Taking the same precautions, as mentioned in the beginning. replace the drives 1 by 1.
once that has been done.
Shutdown server.
remove the large disk.
restart server
In windows, break the mirror.
Use ACU: extend logical drive.
in windows extend the partition.

BR
/jag

Accept or Kudo

Kirk Watson
Occasional Advisor

Re: Expand Disk Array w/ Larger Disks ACU Elegant Solution

gregersenj

Low functionality - It is my understnading the Smart Array Advance Pack which allows for Advanced Capacity Expansion is not available on the E200.

In your scenario, instead of 1 large physical drive, what about second larger logical drive. What is best way to copy from the current logical? Prefer cold copy with bootable media. Then, since both logical arae on same RAID, how to select FIRST drive.. i.e. the one the BOIS will boot to when the E200 card is selected as the boot device?

Note this is Win Server 2008 so boot.ini does not exist...