Windows 10: Rebuilding Failed Parity/Mirror Storage Array Success Story

Just wanted to post this to the internet since there are literally no other posts about this exact scenario, which I could see others running into. Short story - I lost 2 drives in a 4-drive parity array.

I had a shotty storage spaces array in my home desktop comprising of 2x2TB WD Green drives, 1x2.5TB Seagate Green, and a 2TB WD Red in a Storage Spaces array. A small mirror volume spreading all 4 drives was created first, which would host my critical files (this array never failed, by design), and a parity array that filled the remaining capacity, which also spread across 4 drives. I ran in this configuration for over a year before experiencing hardware failures.

First off - Never run green drives. I don't care your reasons for wanting to buy them or receive them for free (sell them if you do), but I've lost several dozen green drives over the last few years. They will fail! They're bottom bin drives that didn't make the cut.

I upgraded my computer case (Cooler Master's HAF XB Evo Lan Box is incredible and worth every penny), and while doing so, accidentally dropped two powered-off green drives about 3" onto a soft surface. I can only deduce that this is what caused the drives that worked pre-case-upgrade to fail. Upon booting the system back up, Storage Spaces started throwing notification errors at me that 1 drives was missing. So I hopped into powershell and ran get-physicaldisk, and one of the drives wasn't showing up in the list. After some quick troubleshooting, I determined the drive was not spinning up after receiving power, and had experienced a major hardware failure. No ability to raw copy any data off the disk, even with external hdd docks. 100% dead. Cool. But with 4 drives in a parity array, I should have been able to see all of the virtual disks and volumes in a reduced resiliency state. When attempting to bring the storage pool online, it would fail and I'd get a notification that there were issues.

So over to event viewer, I found "The device, \Device\Harddisk1\DR1, has a bad block." A quick note - as far as I'm aware - you cannot run chkdsk or other similar utilities on a physical disk that is part of a array. So how to fix bad sectors? I spent some time trying to figure out which device DR1 was, but ended up just running Western Digital's LifeGuard's Diagnostic tool, extended test, on the three remaining physical disks since it can scan drives for bad sectors without depending on an in-tact file system. Two of scans completed fine without issue, but one of them failed the test due to too many bad blocks that it couldn't repair. So how to remove the bad blocks? Fortunately for me, this HDD with bad blocks still spun and raw data could be read, so I placed the bad-blocked drive in a USB dock and ran HDD Raw Copy to a good working drive (3TB instead of 2, but the system didn't care too much). After placing the good drive with the cloned data, I booted up and... the array came online! Storage Spaces was smart enough to not look at UUIDs, models, sn, friendly names, etc, and knew that the totally different drive had the data on it that it needed to complete the array. 95% of my data is perfectly intact. A large video file didn't copy over, but everything else was good to go.

So for other users who experience bad blocks in their storage space array, know that HDD cloning might save you assuming the data on the drive is intact enough.

:)

 

Storage pools, update pool with RAID10

I dont understand that part, how can storage spaces simultaneously mirror and stripe data with only 3 drives? And how does this even protect from drive failures, unless its a parity (RAID5) but
its write performance is insanely poor.

Im running my array this way since windows 10 release and so far i didnt had any issues with it, i went through all possible fail scenarios before i go with it.

What is COW and ReFS? And how it can fail due to file system?

 

Help with Storage Spaces

I am building a large storage array for a friend's sizable media collection. The target is >25 TB usable, and there are currently 6 6TB WD Red drives for the array with an SSD as the boot drive. I want a RAID5 (called "Parity" in the Windows Storage Spaces
options). The Windows 10 setup wizard makes this process very easy and it seems to work quite well. However, we noticed that two drives rather than 1 were missing from the usable capacity of the array (22.5 TB usable out of 33 TB total versus 28 TB out of
33). Two disks, rather than one, were being used as parity drives. This is referred to as RAID6. We tested it out and found that with 3 or 4 disk arrays, the Storage Spaces system defaults to a RAID5 array (i.e. one drive is subtracted from the usable capacity
for parity). I cannot find a way to select which RAID level Storage Spaces utilizes when creating the RAID array.

My question is this: how can I force Storage Spaces to create a RAID5 array versus a RAID6? If there isn't a way to select the RAID level used, there should be. I think that would be fairly simple to explain in a tooltip ("More Space" versus "Better Data
Security"). Alternately, MS could change the number of disks at which the array defaults from RAID5 to RAID6. As it stands, using 5+ disks in a "Parity" (RAID5 or RAID6) array means that you only gain ~10% more space over a simple RAID1 at 5 disks and ~15%
at 6 disks.

I hope there is a simple solution, as he would prefer not to transfer 20 TB of files just to have to rebuild the array when he can get the extra disk back.