Is there a way to force unraid to use a smaller disk as parity?
I have a 4TB drive to use as parity in my array with the largest disk being 4TB but unraid says the parity drive is too small.
I assume the "smaller" drive will be off by a few bytes or kilobytes or whatever which i'm not really fussed about.  If the worst happens and I lose a few kilobytes it's not the end of the world.

 

Edited November 25, 20187 yr by bigmac5753
typo

Go to Tools - Diagnostics and attach the complete diagnostics zip to your next post.

 

What can you tell us about that new disk? Was it shucked from an external drive perhaps?

 

You cannot use a parity disk that Unraid thinks is smaller than any of your data disks, not even by one byte. But maybe we can see why it is smaller and fix it. Otherwise you will have to use a different full-size parity disk and possibly use that one as data.

Thanks for your response, diagnostics attached.

In the SMART / identity section, both drives are the exact same size (4,000,787,030,016 bytes) but it will not allow me to use it.

The new drive (WD elements) is still in a USB3 enclosure and did not plan on shucking but will if it makes a difference?

 

Thanks

server-diagnostics-20181125-1707.zip

You were planning to use a USB connected disk as parity? Do you have other array disks connected USB?

 

Even though Unraid theoretically supports USB connected disks in the array it is likely to be the source of numerous issues including performance and troubleshooting. I especially wouldn't use a USB connected parity disk.

 

Maybe you should tell us more about your system design.

That is the only USB drive.

Specs:

M/B: MSI - Z97-G45 GAMING

CPU: i7-4790K

HVM: Enabled

IOMMU: Enabled

Memory: 32 GB (max. installable capacity 32 GB)

Network: bond0: adaptive load balancing, mtu 4000 
 eth0: 1000 Mb/s, full duplex, mtu 4000 
 eth1: 1000 Mb/s, full duplex, mtu 4000

 

Array consists of 4TB, 3TB, 2TB, 1TB spinners.  500GB, 2x 250GB SSD's  All connect to m/b or PCI-E SATA card.

The only thing I can think of is move all data from 4TB array disk to new disk then use the array disk as parity instead.  I'm reluctant to do this due to the wear on the drive and downtime etc...  but if the sizes appear to be the same, what's stopping the current array drive being too small for parity.

 

 

So you don't have a parity disk presently.

 

If you are determined to use that disk instead of buying another SATA disk, then you might try testing it thoroughly with the WD Diagnostics and if it passes you could shuck it and see if maybe the enclosure is making it appear too small. I wouldn't recommend using it in the enclosure anyway.

 

I don't know if HPA (Host Protected Area) is a possibility here or not. I've never encountered it myself.

 

Here is a link to our wiki with some links to HPA discussions, but they are likely to be old. Or a google search for "unraid HPA" might get some more recent ideas.

 

Maybe someone else will chime in.

The drive is likely appearing smaller because of being in an USB enclousre, if you remove it, and you should, it should be the same size, though WD has been known to use smaller driver for USB enclosures, i.e., even after removing it might still be smaller.

WD also use encrypting USB to SATA bridge chips so anything written to the disk while it's in its enclosure will not be readable if you shuck it. It isn't a problem if you shuck it before you introduce it to the array. It's just something to be aware of.

Shucked the drive, reported size still the same (4,000,787,030,016 bytes). 

It's allowing me to add it now so an 11 hour wait for parity sync.

Thanks guys.