RAID Configuration Question

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mjreiman

9 posts

Wannabe Geek

#56795 24-Jan-2010 05:52

I am new to using RAID. However, at my new job I have to replace one of the drives in an IBM server because it's full. I have six HDDs total in it. 2 arrays, one of four discs, the other of two. How can I replace one of the discs for more storage without losing my RAID configuration? And what's the best way to determine my current RAID level?

Thanks a bunch,
Matt

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BitSignal

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#292740 24-Jan-2010 20:40

You want to increase the capacity or just replace a failing disc?

You can find more about your RAID array if you're allowed to reboot the server. You can then access the controller BIOS (varies with model, on my ones I press Shift+F10). If you can't reboot, finding the information you want depends on what tools are installed and what the OS is.

If it's a straight swap (remove failed disk, put new one in) and you have hot-swappable drives, just pull the failed one out and insert the new one, then it should rebuild itself automatically.

"Roads? Where we're going, we don't need roads." - Doc Emmet Brown

mjreiman

9 posts

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#292754 24-Jan-2010 21:55

thanks man. yea i'm just putting a new disc in because alot of the discs in there are really small capacity discs. so i figured if i just put a new disc in it should collect the data and rebuild the disc without having to reinstall the os or anything. i'm running windows server 2003 and i can restart the server, but since it's at work it effects the company database and closes the domain connection temporarily. but i am using IBM ServeRAID Manager as the application.

magu

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#292811 25-Jan-2010 06:39

Ok, so use the ServeRAID Manager to tell what array type you're using.

Replace each of the disks until all of them are of the same size again, then you *may* be able to expand the size of the array. But check with your ServeRAID manual to ensure it is capable of resizing the array. Also bear in mind that not all RAID configurations are expandable.

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ald

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SimWorks

#292848 25-Jan-2010 11:08

Easy things that we've done with RAID - replace a failed disk in the array, add a new disk to the array.

Expanding the array capacity by adding in bigger disks one by one and then expanding - sounds tricky! I'd definitely take a very careful look at your documentation. And if it all goes pear shaped you'll want a fall back strategy in terms of your data ...

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browned

636 posts

Ultimate Geek

#292854 25-Jan-2010 12:23

Haven't seen many raid controllers that can expand capacity by adding bigger disks without a complete trash and rebuild of the array. Some controllers can do it, but you need to contact the manfacturers user support and send them information about the the old disks and new disks and arrays. This can take time and can result in all being lost anyway.

I would do some research on your raid controller first to see what make/model it is and also do some research on RAID in general so you can understand it before you get started and possible lose data or waste money on new parts you can't use.

The most common way to do Online Capacity Expansion is by adding a completely new disk (same size or larger as current disks) into the array with all of the old disks and let the raid controller do the OCE. This can sometimes only be done with Online Raid Level Migration (say from RAID 1 to RAID 5).

Key to successfully playing with most RAID setups. Never remove more then one disk at a time. Don't press yes/ok unless you know what the outcome will be.

The last time I upgraded the capacity of a RAID array I backed up all the data, upgraded all the disks one at a time, confirmed each new drive had been successfully rebuilt and RAID was healthy. Copied all the data to a spare disk/did another backup of the data. Then and only then trashed and rebuilt the array using the larger disk space. Then copied the data back.

EDIT: Oh and if you are successful in expanding the raid you will then need to use Microsofts "DiskPart" command line tool to expand the actual size of the partition on the array. This is not hard but it should be noted that it cannot be done on system partitions (ie Boot drives, System drives or drives with pagefiles on them).

EDIT2: Info about OCE
OCE - http://ask.adaptec.com/scripts/adaptec_tic.cfg/php.exe/enduser/std_adp.php?p_faqid=3883&p_created=1025301240&p_topview=1

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jaymz

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#293111 26-Jan-2010 11:39

Probably the best and easiest option in my opinion would be to image the array (the partitions on the array) with ShadowProtect or Ghost then install your new disks and build an array on them, then restore the image(s) back onto this new array.

I recently did this with a client with the exact same issue (they didnt want to fork out for a whole new server) and it worked fine. They had a full disk bay too (ie no new disks could be added next to it)

As always, make sure you double check and test your images are working fine before deleting any RAID arrays.

Once you have your partitions back on your new array you can use acronis or some other disk partitioning software to resize the disk partitions acordingly. (Again Test, Test and retest the backups)

Regs

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Snowflake

#293159 26-Jan-2010 15:11

browned: Haven't seen many raid controllers that can expand capacity by adding bigger disks without a complete trash and rebuild of the array. Some controllers can do it, but you need to contact the manfacturers user support and send them information about the the old disks and new disks and arrays. This can take time and can result in all being lost anyway.

the serveraid controllers in two of the ibm servers I have can both expand and shrink arrays without destruction no problem. it just takes a while for it to finish....

....but i never trust raid controllers so I *always* back up the data first!

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mjreiman

9 posts

Wannabe Geek

#294748 30-Jan-2010 22:16

would Acronis True Image Enterprise Echo Server be an okay image program to use? the server is old and has just BARELY enough RAM to run the newest version of ghost. i know it's sad for the minimum requirement being 1GB

rphenix

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#296920 7-Feb-2010 22:05

mjreiman: would Acronis True Image Enterprise Echo Server be an okay image program to use? the server is old and has just BARELY enough RAM to run the newest version of ghost. i know it's sad for the minimum requirement being 1GB

Yes acronis make a very good imaging product.

jaymz

1133 posts

Uber Geek

#296961 8-Feb-2010 08:02

mjreiman: would Acronis True Image Enterprise Echo Server be an okay image program to use? the server is old and has just BARELY enough RAM to run the newest version of ghost. i know it's sad for the minimum requirement being 1GB

ShadowProtect IT edition does not require you to install anything, you can boot it from the CD. Means imaging less grunty machines is easier.

mjreiman

9 posts

Wannabe Geek

#296970 8-Feb-2010 09:20

So in order to simply expand the storage space of the server, I can simply put a new drive in with a higher capacity and let it rebuild the data so the server has more space on it? I just wanna make sure I'm unerstainding all this right before I mess around with the companies data. This server is old so it doesn't have like a simple usb port for me to put everything on the external hard drive in case I lose everything.

magu

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#296973 8-Feb-2010 09:42

If you can, find a network attached storage device and BACKUP all the data, then you can try. Some RAID controllers accept it, some don't.

In ANY scenario, BACKUP is the first step.

Oh, and did I mention BACKUP first? :D

"Roads? Where we're going, we don't need roads." - Doc Emmet Brown

mjreiman

9 posts

Wannabe Geek

#296976 8-Feb-2010 09:52

That's part of my dilemma. I have a NAS connected to the LAN switch that reads over the network because that's where I'm planning to pull my Acronis images from. The drive is visible but not accessible. Whenever I go to open it, I get a message saying "There is not enough storage space to perform this action." I'm assuming it's because of the low amount of free space that's left. The server is on a rack pushed back in the corner so there may be a USB port in the back I can attach the NAS though since I can't access it via Ehternet.

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browned

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Ultimate Geek

#297016 8-Feb-2010 11:52

mjreiman: So in order to simply expand the storage space of the server, I can simply put a new drive in with a higher capacity and let it rebuild the data so the server has more space on it? I just wanna make sure I'm unerstainding all this right before I mess around with the companies data. This server is old so it doesn't have like a simple usb port for me to put everything on the external hard drive in case I lose everything.

Sounds to me like this very old server wouldn't have Online Capacity Expansion or Online Raid Level Migration features available so rule those out.

Seeing as it is a very old box I would expect it to have a relatively small total HDD config, you haven't let on any important details about RAID setup or size so one would assume it might have 2 x 36GB raid 1 mirror and 3 x 146 GB raid 5 therefore a total capacity of about 350GB.

I would open the server, look for a standard HDD connection (IDE, or SATA) and buy a basic 500GB hard drive for a image based backup. Of course all data should be backed up on tape or some other form of backup medium before any disk is removed or wiped.

Then since you are not going to be able to do OCE or ORLM get new larger disks for the arrays that need upgradings, image the old disks, remove them and mark them incase they need to be restored to the array, pull the old ones, insert the new ones configure the arrays and put the imaged data back. test and done.

Really I think if you are not sure about any of this it would be best to get someone who is sure involved. Learn from them and not make any mistakes as it could be very very costly for you and the company.

rphenix

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#297040 8-Feb-2010 13:42

magu:
In ANY scenario, BACKUP is the first step.

Oh, and did I mention BACKUP first? :D

Can't recommend backing up enough and doing so in MULTIPLE ways. We have a policy of at least 2 images (using different technology) at work, along with pulling the original drives from the array so they were intact and then adding all new ones on important servers.

Some of the problems Ive had in the past include:
    * Restore simply erroring at certain percentage through restore (say 90%, or 75% through).
    * USB 2.0 transfer speeds slow as USB1, eSata transfers slowly, Gigabit transfer is slow.
    * Flakey onboard Sata Ports.
    * Add-in sata card issues with live cd recovery enviroment (this has gotten much better with new versions of recovery software).
    * Data restore completes, no hardware changes that should affect HAL yet system doesnt boot for one reason or another.
    * Restore LiveCD enviroment refuses to boot or boots very very slowly with recovery media connected (older versions of BESR were good at this).

+many other issues for example there was an Intel chipset out there that when using an earlier version of clonezilla to only read from the array caused the array to degrade and fail to boot.... that was a good one.

The most reliable software for restoring from an image I've found is Shadowprotect. Acronis's recovery enviroment was linux based meaning drivers could be spotty (fine from within windows if you have a spare server) BESR while windows based for the live cd could also give quite a bit of grief in early versions. We never lost data but we certainly took longer to restore than antipated thanks to issues.

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