The Tier pool is configured by tiering sub-pools.
By setting differences in (tiering) the access performance of the sub-pools, appropriate data location according to access frequency is possible.
The access performance of sub-pools differs depending on the types of disks that configure the sub-pool, the RAID level, and the number of disks.
For this reason, it is possible to configure a sub-pools with not only the type of disk such as SSD, Online SAS, Nearline SAS, SED-SAS, Online SED, SSD SED, Nearline SED, but with identical disk types having different RAID levels or numbers of Member Disks.
In addition, by using the automatic disk selection function, instead of selecting the number of Member Disks, it is possible to configure sub-pools by specifying the disk capacity.
In creating the Tier pool, configure sub-pools while taking into account the priorities listed below.
Refer to *3 of "1.2 Operating Environment" for the terms of use of each type of disk.
Priority | Disk Type | Number of Data Disks | Number of Member Disks | RAID Level | ||||
|---|---|---|---|---|---|---|---|---|
1 | SAS SSD | 20 | (4D+2P)*5+1HS | RAID6-FR | ||||
2 | 24 | (8D+2P)*3+1HS | RAID6-FR | |||||
3 | 12 | (6D+2P)*2+1HS | RAID6-FR | |||||
4 | 12D+12D | RAID1+0 | ||||||
5 | 12D+1P | RAID5 | ||||||
6 | 8 | (4D+2P)*2+1HS | RAID6-FR | |||||
7 | 8D+8D | RAID1+0 | ||||||
8 | 8D+1P | RAID5 | ||||||
9 | 8D+2P | RAID6 | ||||||
10 | 7 | 7D+1P | RAID5 | |||||
11 | 6 | 6D+2P | RAID6 | |||||
12 | 4 | 4D+4D | RAID1+0 | |||||
13 | 4D+1P | RAID5 | ||||||
14 | 4D+2P | RAID6 | ||||||
15 | 3 | 3D+1P | RAID5 | |||||
16 | 2 | 2D+2P | RAID1+0 | |||||
17 | 1 | 1D+1D | RAID1 | |||||
18 | ONLINE SAS | 20 | (4D+2P)*5+1HS | RAID6-FR | ||||
19 | 24 | (8D+2P)*3+1HS | RAID6-FR | |||||
20 | 12 | (6D+2P)*2+1HS | RAID6-FR | |||||
21 | 12D+12D | RAID1+0 | ||||||
22 | 12D+1P | RAID5 | ||||||
23 | 8 | (4D+2P)*2+1HS | RAID6-FR | |||||
24 | 8D+8D | RAID1+0 | ||||||
25 | 8D+1P | RAID5 | ||||||
26 | 8D+2P | RAID6 | ||||||
27 | 7 | 7D+1P | RAID5 | |||||
28 | 6 | 6D+2P | RAID6 | |||||
29 | 4 | 4D+4D | RAID1+0 | |||||
30 | 4D+1P | RAID5 | ||||||
31 | 4D+2P | RAID6 | ||||||
32 | 3 | 3D+1P | RAID5 | |||||
33 | 2 | 2D+2P | RAID1+0 | |||||
34 | 1 | 1D+1D | RAID1 | |||||
35 | NEARLINE SAS | 20 | (4D+2P)*5+1HS | RAID6-FR | ||||
36 | 24 | (8D+2P)*3+1HS | RAID6-FR | |||||
37 | 12 | (6D+2P)*2+1HS | RAID6-FR | |||||
38 | 12D+12D | RAID1+0 | ||||||
39 | 12D+1P | RAID5 | ||||||
40 | 8 | (4D+2P)*2+1HS | RAID6-FR | |||||
41 | 8D+8D | RAID1+0 | ||||||
42 | 8D+1P | RAID5 | ||||||
43 | 8D+2P | RAID6 | ||||||
44 | 7 | 7D+1P | RAID5 | |||||
45 | 6 | 6D+2P | RAID6 | |||||
46 | 4 | 4D+4D | RAID1+0 | |||||
47 | 4D+1P | RAID5 | ||||||
48 | 4D+2P | RAID6 | ||||||
49 | 3 | 3D+1P | RAID5 | |||||
50 | 2 | 2D+2P | RAID1+0 | |||||
51 | 1 | 1D+1D | RAID1 | |||||
Free space of the reserved area size required for evaluation/relocation is required for each sub-pool in a Tier pool. If free space cannot be allocated, evaluation/relocation fail.
The reserved area required for evaluation/relocation varies with the storage device as follows.
Storage Device | Reserved Area Required for Evaluation/Relocation |
|---|---|
ETERNUS DX S4 series (excluding DX60 S4) | 7.88 GB * (Number of layers of Tier pool) |
ETERNUS DX S2 series (excluding DX60 S2) | (Total capacity of Tier pool) * 10 % |
