Hello,

 

I didn't understand everything about the disk parity under unraid, so I directly ask the question.

 

I have the following records:

Parity    WDC_WD60EFRX-68L0BN1_WD-WXN1H848JW7R - 6 TB (sdo)    
Disk 1    ST6000DM003-2CY186_WF3064WN - 6 TB (sdk)        
Disk 2    ST6000NE0021-2EN11C_ZA10WSFH - 6 TB (sdn)        
Disk 3    ST6000NE0021-2EN11C_ZA18ASMB - 6 TB (sdp)        
Disk 5    SAMSUNG_HD204UI_152D00539000-0:0 - 2 TB (sdc)        
Disk 6    SAMSUNG_HD204UI_S2HGJ90B804566 - 2 TB (sdl)        
Disk 7    SAMSUNG_HD204UI_S2HGJ90BA05489 - 2 TB (sdm)        
Disk 8    WDC_WD10_00DHTZ-04N21V0_152D00539000-0:1 - 1 TB (sdd)        
Disk 9    ST975042_0AS_152D00539000-0:5 - 750 GB (sdh)    40 C        
Disk 10    ST975042_0AS_152D00539000-0:6 - 750 GB (sdi)    41 C    
Disk 11    APPLE_HD_D_ST500LM012_152D00539000-0:3 - 500 GB (sdf)    
Disk 12    ST500LM0_12_HN-M500MBB_152D00539000-0:2 - 500 GB (sde)

 

Is the parity disk sufficient for 27.5TB of data or not at all???

 

Thank you in advance for your answers

you parity Disk needs to be the same or Bigger than your biggest data disk. So the 6 TB is good. So with 1 parity 1 disk may fail and you in theory still keeps all data.

 

if you get more disks you might think about a second party disk. Many ppl say 1 parity till 20 disks works ok.

57 minutes ago, Falcom said:

Is the parity disk sufficient for 27.5TB of data or not at all

Parity is not a backup. Parity by itself can recover nothing. The fact that parity by itself doesn't have any of your data is why it doesn't have to be as large as your data.

 

Parity PLUS ALL remaining disks allow a missing disk to be recovered.

 

Parity is a common concept in computers and communications, and it is basically the same wherever it is used. Parity is just an extra bit that allows a missing bit to be calculated from all the other bits.

 

Here is the wiki on parity:

https://wiki.unraid.net/UnRAID_6/Overview#Parity-Protected_Array

 

I notice some of your disks are rather small. I don't recommend using lots of small disks just because you have them.

 

Each additional disk is an additional point of failure. Each additional disk requires additional ports, and at some point, higher Unraid license level. Smaller disks don't perform as well as larger disks due to data density. Possibly some of those small disks are old and maybe unreliable. Since all disks are required to recover a missing disk, it is important that all disks in your array be reliable.

 

In order to reliably rebuild every bit of a missing disk, Unraid must be able to reliably read every bit of all other disks.