Raid Help

[alex190304]

Hi so I need your opinions on this backup NAS so here is my planned config:

 

Server: HP Proliant DL180 G5

 

Raid Controller: LSI LOGIC MEGARAID SAS 8888ELP 8-PORT 512MB

 

Raid Config:

 

Total usable storage capacity (GB) = 16000

 

RAID Type: RAID6 (Stripe set with double parity)
Number of RAID groups = 1
Number of drives per RAID Group = 4
Total number of drives = 4
Drive capacity (GB) = 8000
Capacity of a single RAID group (GB) = 16000

Space efficiency = 0.5 (50%)
Fault tolerance = 2 disk drives per RAID group
IO penalty (read) = 1/1 (one RAID IO per each host IO)
IO penalty (write) = 6/1 (6 RAID IOs per each host IO)

Minimum number of drives per RAID6 group = 4.

 

Thanks.

Alex

[dalekphalm]

Hi so I need your opinions on this backup NAS so here is my planned config:

 

Server: HP Proliant DL180 G5

 

Raid Controller: LSI LOGIC MEGARAID SAS 8888ELP 8-PORT 512MB

 

Raid Config:

 

Total usable storage capacity (GB) = 16000

 

RAID Type: RAID6 (Stripe set with double parity)

Number of RAID groups = 1

Number of drives per RAID Group = 4

Total number of drives = 4

Drive capacity (GB) = 8000

Capacity of a single RAID group (GB) = 16000

Space efficiency = 0.5 (50%)

Fault tolerance = 2 disk drives per RAID group

IO penalty (read) = 1/1 (one RAID IO per each host IO)

IO penalty (write) = 6/1 (6 RAID IOs per each host IO)

Minimum number of drives per RAID6 group = 4.

 

Thanks.

Alex

You might consider doing a RAID 10 setup instead of RAID 6 with just 4 drives. You'll get the same failover protection (2 drive failures), but overall performance should be a bit better.

 

Ideally, I would suggest adding in one or two extra HDD's, if you can afford it, and doing a RAID 6 with 5 or 6 HDD's.

 

I actually have that RAID Card, but I'm just using it as an HBA, essentially.

[braneopbru]

You might consider doing a RAID 10 setup instead of RAID 6 with just 4 drives. You'll get the same failover protection (2 drive failures), but overall performance should be a bit better.

 

Ideally, I would suggest adding in one or two extra HDD's, if you can afford it, and doing a RAID 6 with 5 or 6 HDD's.

 

I actually have that RAID Card, but I'm just using it as an HBA, essentially.

Agreed.

 

Raid 6 with 4 drives makes absolutely no sense at all. With only four drives, RAID 10 is the way to go.