Adding a smaller drive to a RAID?

dsiomtw

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May 2, 2011
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I currently have 2 160GB velociraptors in a RAID 1. One of the drives died yesterday and I've decided to upgrade to SSDs. The velociraptors are 160GB but I'm only using a total of 80GB in 2 partitions. The rest of the space is unformatted.

My question is simple - can I replace the dead 160GB velociraptor with say a 120GB SSD? Then once that new drive is synced I can remove the working velociraptor and stick in the other new 120GB SDD?

I guess I just want to make sure the new drive will be rebuilt properly if it has less capacity than the existing drives (although more capacity than is physically in use).
 
I would think that the rebuild, which happens on a drive level instead of a partition level, would not work. I would do it in what I consider to be an easier way.

Build a RAID1 with the two SSDs and then copy what's on the remaining Raptor to them.

Please consider all standard warnings about TRIM not going through RAID arrays to have been given. Actually, if you mirror them in Windows instead of in the BIOS, you probably will get TRIM. If you care.
 
Hmm not sure I know enough to do all of that. My current drives/RAID have my operating system and all my programs, data, etc. (My entire system is only about 25GB - I don't use a ton of space).

I'm not sure I would know how to "build a RAID 1 with the two SSDs and then copy what's on the remaining Raptor to them". I have a backup of both partitions, are you saying that I could basically start from scratch and build a new RAID with the 2 new SSDs, and then just restore my backups to them??

I have XP so TRIM is a no-go either way. I'm looking at getting Kingston V+ 100 or Intel 320 series SSDs as they seem to have the best GC for use with a TRIM-less OS like XP.

Thanks!
 

You've already done all the steps before! You built a RAID from the Raptors, yes? Plug in the two SSDs (if you have enough free SATA ports) and follow the same process to RAID them. Then the OS will see two volumes, the old 1-disk volume and your new two-disk volume. Clone from the old to the new.

Or, you could indeed take a backup (and test it), remove the current drive, start over installing the two SSDs in RAID1, and then restore the backup to the new volume. Either way is just a drive clone, with the first way having both drives live on the PC at the same time, and the second way using an image dump as an intermediate.

Could you be more specific about what doesn't make sense, please?
 
Sorry I'm just a newbie to all this stuff. I bought the computer from Dell and it was already all configured. I've added RAM to a few desktops but that's about it so far!

I just popped open the computer and see I have 2 more SATA ports so that's good, so I should be able to do what you're describing. I have one available power connector from the dead raptor so I'll need to get something to piggyback off of that to provide power to the 2nd SSD I assume...

OK so just to clarify ... if I go with "option 1" ... I'll setup a new RAID with the new SSDs. I'll need to somehow partition this to create 2 new logical drives with 2 new drive letters, say E and F. (Do I need special software for this?) Then I can restore my C and D drive backups to the new E and F drives on the SSDs.

Then what? Would I go into the BIOS or something and set E (which is a clone of C) as the new boot drive? Then I can remove the last raptor and eliminate the original array, and maybe at the very end change the drive letters on the SSDs from E and F back to C and D so all my stuff will work properly??

Sorry for being such a dunce. At least I somewhat understand what you're saying and can see it working. I'm off to buy 2 SSDs. Since I only use about 25GB total and never plan on needing much more than that, I can get by with 60GB SSDs which is cool.

I guess my other option to simplify things is to just spend the extra money to buy SSD drives LARGER than my current 160GB drives, in which case I imagine I could just plug one in in place of the dead raptor and it will be rebuilt automatically. I guess I'll see what the price difference is and decide...

Thanks!
 
Ahh, it came pre-configured with the RAID1. Now I understand. My mistake for assuming that you had set up the RAID1. But Dell makes it more interesting...

if I go with "option 1" ... I'll setup a new RAID with the new SSDs. I'll need to somehow partition this to create 2 new logical drives with 2 new drive letters, say E and F. (Do I need special software for this?) Then I can restore my C and D drive backups to the new E and F drives on the SSDs.
With option 1, you don't use the backups. You pop the two new SSDs onto the two remaining SATA ports, splitting power to them. Note that with a Dell motherboard, you may have to go into the BIOS and enable both of those ports by hand - many Dell BIOSes aren't smart enough to detect the addition or removal of a drive. If you are offered a choice of IDE/AHCI/RAID mode, choose RAID.
Then boot to BIOS again. Look for a message that says something like "Press CTL/A to configure RAID." Press CTL/A to interrupt it at this point. In the new menu that comes up, you will build a RAID1 array out of the two SSDs. (Sorry, I don't know how, but it should be close to evident).

Then you boot to Windows. The new RAID volume will be seen as a single blank disk in Disk Manager (Control Panel - Administrative Tools - Computer Management, and then Disk Management). Stop me now and ask for extra advice if you are running Windows 7. Otherwise, right-click on the picture of the blank space in this new volume, initialize it as an MBR volume, right-click again, choose to create a partition, make one the size of your C, then repeat for D.

Now clone from your existing drive to your new "drive," either by using cloning software or doing a Win7 system dump booted from the old drive and a restore booted from the Windows DVD.

Then what? Would I go into the BIOS or something and set E (which is a clone of C) as the new boot drive? Then I can remove the last raptor and eliminate the original array, and maybe at the very end change the drive letters on the SSDs from E and F back to C and D so all my stuff will work properly??
Slightly easier. After the clone, power off. Disconnect the old drive. Your system will choose to boot from the new drive, which was made bootable by the clone process, because it's the only bootable device. (again, if this is a picky Dell BIOS, you may get error messages about the missing drive and have to disable its port in BIOS). The boot partition will be made C, the next partition will be made D, and presto, you will be running.

And if anything goes wrong during this process, you can stick your original disk back in and boot up from that. Then cuss me out, give details, and try again.

Finally, there is a (low) chance that the transferred system will boot partway and hang. In that case, boot from the OS DVD and choose a Repair install.

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Let's get more specific.
What OS are you running?
Do you have a backup program, and will it do image backups booted from its own CD (if not, Win7 will do it for you)
Do you want to clone via an external backup, or directly from the old drive to the new volume?
Do you have an external drive and, if so, is it USB, USB 3.0, or eSATA?

 
Thanks for all your help, I'm already back up and running on the SSDs. It was pretty painless. I created the new RAID and created 2 partitions and just assigned them random drive letters. Then I used my Acronis True Image to restore my C and D partitions to the new partitions. Once I did this, I powered down, removed the raptors and put the 2 new SSDs in their places. It booted just fine and the 2 partitions inherited the correct drive letters C and D just fine.

My first thought ... it seems zippier ... but the strangest thing is the silence. For some reason the lack of noise makes things seem to take longer for some reason lol

Thanks for all your help!