I converted my system to two RAID 0 2 TB SSDs, so I have one C: drive using both SSDs.
I created the RAID 0 array using Ctrl-I on boot. I then restored a Macrium image. After I did that, I booted up Windows 10 Pro, and I looked at Disk Management, and I thought I would see an active partition and an unallocated (what I have seen in the past), both of say about 1900 GB. What I saw though was an active partition ~900GB, unallocated ~1000 GB, and a second of about 1700 GB. I am sure this happened because the backup image was ~900GB.
So in Disk Management it let me extend that first active partition, the C: drive, so now I see this:
Drive C is now 2048 GB (a full 2 TB), the unallocated (second drive in the RAID 0 array) is only 1767 GB. Is this going to be a problem? I thought a RAID array would equally divide things so I get the usable disk size of one physical drive. Or is this just a reporting error in Disk Management? I ran a chkdsk /f and it didn't seem to complain about anything, I am wondering if I really have access to the space it shows as available on the C: drive, 2 TB, though?
This is what Intel RST shows:
The 2tb Sata II drives here show 1.838gb when first installed before the data went on. The 1.767gb you are seeing for the second SSD is normal since the OS and files are still found on the first portion of the single primary you are spanning across the two drives and not seeing mirrored. This is how the array is working for you there.
A Spanned array is when two or more drives will see a single partition spread across every drive in the array which usually see smaller size drives and mostly seen with data server application rather then desktop. Once you restored the image made and expanded it onto the second drive that automatically ruled out seeing it made into a mirror of the first.
Ah - I thought that when I coupled two drives as a RAID 0 array, that data copied onto the array would be striped evenly across the two drives so the report would always show same size for the individual disks and same amount of data in use. The data is not striped evenly here it would appear.
Striping keeps the data evenly spread across multiple drives in what's called "Stripe Bands". The access speed may depend on the slowest drive or when having identical drives see the even spread while still seeing a single volume but in bands. Spanning on the other hand is not even a RAID 0, 5, or 10 situation but simply one giant primary reaching out across two or more drives.
Now since you are reporting an uneven distribution that suggests you may have simply ended up with a spanned volume with the OS installation and programs right up front on the first drive of the span itself. Some basic information about this is found in the WD support pages as well as a few other references. WD Support
Now the main reason for the discrepancy is not that the drives were not set up in RAID 0 but you restored a system image onto the new array that ended up spanning the two drives. If you had made an image from an identical array and saw that restored the data would have been evenly distributed as it was originally on the array the image was made from.
The image you have there however was based on a single OS drive and once restored was expanded resulting in the span taking place. You saw an unintended span of the array itself while the bios still sees the drives in the RAID 0 array.
Thanks Night Hawk! Nothing to worry about though, right? I still get RAID 0 functionality?
It should function normally while not actually being the end result you would typically when putting a fresh Windows install on. The problem there just happens to be software as far as where the image came from.
As long as the image was good and it was fully restored everything should function normally. If you should run into any issues later however you might end up having to plan a clean install just as word of caution. That would be if the situation degraded fast on you however.
Here I would have started off with a fresh clean install and then made the system image backup from that once everything was on. Generally when planning ahead for a move like this you would look at seeing a clean install to insure everything goes on and works well. First you will need to see how things progress from this point however.
Thanks. All seems fine so far.
That's good to hear then! Just remember if the time comes for needing a clean install you won't have to switch any bios setting! All you would need to do is back everything up from the array you want to keep if not already storing on other drives and nuke the present spanned volume to get the Striped bans you were looking to see.
Hopefully the restored image will hold up and run trouble free for some time before that comes up however to allow you to work things out a head of time. A full wipes of everything would then be needed to get to where you want to be when that time arrives.
