Parity drive just a tiny bit smaller

[DJCorpus]

Hi, I'm running an array of two 1TB drives and a SSD cache, now I want to add a parity drive. I know that the parity drive has to be the largest unfortunately drive I got is about 30MB smaller (976762552 KB vs 976729056 KB). 

As this is a on a budget build and I'm using what I have lying arround and not being used I would prefer to use this particular smaller disk for parity (it's older, has some problems and I don't trust it so much and I'd prefer it to fail than a data disk).

Is it possible to resize currently used disks in array so they have the size of the smaller parity drive? Possibly without losing/moving data?

Or is there any other solution?

[JorgeB]

10 minutes ago, DJCorpus said:

Is it possible to resize currently used disks in array so they have the size of the smaller parity drive?

Possibly using HPA.

 

11 minutes ago, DJCorpus said:

Possibly without losing/moving data?

Not AFAIK.

 

11 minutes ago, DJCorpus said:

Or is there any other solution?

Maybe the smaller disk has HPA enable, and inf that's the case you could remove it, diagnostics would show.

[DJCorpus]

I've checked, all the drives in SMART have the same size of 1,000,204,886,016 bytes [1.00 TB]

 

hdparm -N for

 

2x Seagate drives:

 max sectors   = 1953525168/1953525168, HPA is disabled

 

1x WD:

SG_IO: bad/missing sense data, sb[]:  70 00 05 00 00 00 00 0a 00 00 00 00 24 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 max sectors   = 1953525168/1(1953525168?), HPA setting seems invalid (buggy kernel device driver?)

 

Besides the error, number of sectors is the same.

[JorgeB]

If the number of sector is the same then they are all the same size, but if Unraid complaints then please post your diagnostics so we can see what's the problem instead of guessing.

 

 

 

 

[DJCorpus]

Yeah it looks like it, but Unraid doesn't allow to use it as a parity drive because it's smaller. I added the disk to the array and after formating to xfs the size differs.

 

[JorgeB]

4 hours ago, johnnie.black said:

please post your diagnostics so we can see what's the problem instead of guessing.

 

[DJCorpus]

Sure, sorry that I didn't send it earlier.

unraid-diagnostics-20181117-0702.zip

[JorgeB]

You're using USB disks as array devices, that's not recommended, and it's normal for some external disks to be a little smaller than normal, especially disks from WD.

[DJCorpus]

Ok thanks for the help, I'll probably go with another drive or use the other one for parity then, because resizing them seems a bit overcomplicated.