Technical information
30 EqualLogic Configuration Guide | Version 15.2 | August 2014
7.4 RAID 5 drive layouts and total reported usable storage
RAID 5 (striped disks with distributed parity) will combine N disks in an arrangement where each stripe
consists of N–1 disks that contain data blocks plus 1 disk that contains a parity block. For each stripe, the
parity block will be placed on a different disk ensuring that the parity blocks are not located on a single
disk in the RAID set. RAID 5 implementations can tolerate a single drive failure without data loss.
Table 9 shows the drive layouts that are enforced when using a RAID 5 policy based on the number of
drives in each array/hot spare configuration, and the total usable storage available for each model.
Note: RAID 5 is not supported for PS6210.
Table 9 RAID 5 drive layouts and reported usable storage available with hot spares (in GB)
Disk drives
Hot spare
No hot spare
6
5 Data/Parity + 1 Hot Spare
RAID Policy for RAID 5 without a hot spare is
not supported
7
6 Data/Parity + 1 Hot-spare
8
7 Data/Parity + 1 Hot-spare
12
(a)
11 Data/Parity + 1 Hot-spare
14
13 Data/Parity + 1 Hot-spare
16
15 Data/Parity + 1 Hot-spare
24
(a)(b)
23 Data/Parity + 1 Hot-spare
48
(b)
46 Data/Parity + 2 Hot-spares
(a) PS4100/PS6100 models only
(b) 24 and 48 drive arrays implement multiple RAID 5 sets within a chassis
Total reported usable storage when using hot spares: All models prior to PS4100/PS6100
Drive
qty / Size
50
(a)
100
(a
)
74
146
250
300
400
450
500
600
750
1000
2000
3000
7
(b)
-
-
-
-
1111
-
-
-
-
-
-
-
-
-
8
(c)
-
-
-
-
1333
-
-
-
-
-
-
-
-
-
14
(d)
-
-
792
-
2671
-
4281
-
5354
-
-
-
-
-
16
621
1244
-
1827
3118
3744
4995
5622
6247
7500
9378
12508
25456
38461
48
-
-
-
-
-
-
-
-
19452
23345
-
38916
74580
115394
Total reported usable storage when using hot spares: PS41x0/PS61x0
Drive
qty / Size
146
200
(e)
300
400
(e)
500
600
900
1000
2000
3000
6
-
-
-
-
1781
2129
-
3563
7280
11008
12
1300
1843
2672
3696
4454
5355
8038
8929
18186
27473
14
1565
-
3206
-
5353
6426
9645
10719
-
-
24
2744
3880
5620
7772
9379
11253
16855
18728
38184
57698
(a) Solid State Disk
(b) Legacy PS50E
(c) PS4000E and PS6000E only
(d) Legacy PS70E,PS100E, PS100X, PS200E, and PS300E
(e) PS6100S (SSD) only