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How to calculate real size of PG in Blocks?

Question asked by Maksym Tatarenko on Jan 15, 2018

Hello,

I've created PG using four drives (3D1P).

 

# raidcom get parity_grp -IH1

T GROUP  Num_LDEV  U(%)  AV_CAP(GB) R_LVL  R_TYPE SL  CL  DRIVE_TYPE

R 7-1   0 0  3220 RAID5  3D+1P 0 0  DKR5E-J1R2SS

 

 

# raidcom get drive -IH1

LOCATION TYPE  RPM TOTAL_CAP(GB) CODE  USAGE STS GROUP

...

0-16 SAS 10000  1200 DKS5H-J1R2SS  DATA  NML 7-1

0-17 SAS 10000  1200 DKS5H-J1R2SS  DATA  NML 7-1

0-18 SAS 10000  1200 DKS5H-J1R2SS  DATA  NML 7-1

0-19 SAS 10000  1200 DKS5H-J1R2SS  DATA  NML 7-1

 

Is it any command to see capacity of PG in Blocks?

How can I calculate number of total Blocks in PG to create LDEVs?

 

Try to calculate:

3220 * 1024 * 1024 *1024 /512  =  6752829440 Blocks in PG in theory.

But on practice I can use more then 6752829440  Blocks to create LDEVs.

 

# raidcom add ldev -ldev_id 31 -parity_grp_id 7-1 -capacity 3221159424 -IH1

# raidcom add ldev -ldev_id 32 -parity_grp_id 7-1 -capacity 3221159424 -IH1

# raidcom add ldev -ldev_id 33 -parity_grp_id 7-1 -capacity 310510693 -IH1

 

3221159424+3221159424+310510693 = 6752829541

 

WHY?

How to calculate real size of PG in Blocks?

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