Lacie Big5 Raid Problem Drives

[cridwan]

I use lacie 5big with raid setting 5 for 4 drives with 8TB capacity.

The conditions are as follows:
1. Raid 0 with 4 drives, generated capacity: 1.1 TB (?)
2. Raid 0 with 3 drives, generated capacity: 1.1 TB (?)
3. Raid 5 with 4 drives, generated capacity: 1.1 TB - (?)
4. Raid 5 with 3 drives, generated capacity: 14.6 TB - (ok)

I think there is damage to one HDD or slot drive, but all HDD and slot drives normal condition after I do a test with raid 5 with 3 drives randomly (drive 1 + drive 2 + drive 3 or drive 1 + drive 2 + drive 4 or drive 1 + drive 3 + drive 4 ... etc) the result is 14.6TB (normal), meaning all drives work well when using raid 5 with 3 drives.

For your information:
- 4 HDD WD Red Nas 8TB
- All normal and healthy HDD conditions (test with sentinel)

My question, Why:
1. when using raid 0 with 3 drives or 4 drives generated capacity is not as expected (1.1TB)
2. When using raid 5 with 4 drives the resulting capacity is not as expected (1.1TB)

Please help and share it if anyone ever experienced the same thing.

Tks & rgds
Ridwan

 

[Ralston18]

Could working through the various drives pairing two at time in RAID 0 help identify a problematic drive? Or problematic pair?

E.g. Where "Drive" is actually one of the 8TB HDD's.

Drive 1 + Drive 2
Drive 1 + Drive 3
Drive 1 + Drive 4

Then to

Drive 2 + Drive 3
Drive 2 + Drive 4

Drive 3 + Drive 4

With all drive pairings expected to present a usable capacity of 14.9 TB as I understand the calculators.

Probably could work in a round of slot switching per any existing rules regarding how the slots are to be filled.

Also: the 1.1 TB is interesting. If you wanted to do that (i.e., have a "Usable Capacity" of 1.1 TB) how would you go about doing so, reverse engineering so to speak.

Could that 1.1 TB the result of somehow having RAID10 set instead of RAID 0?

Just thinking out loud and trying to help and share.