Datasheet
8068ch08-Storage Pools.fm Draft Document for Review January 29, 2013 12:52 pm
306 IBM Flex System V7000 Storage Node Introduction and Implementation Guide
Figure 8-12 Recommended configuration
The recommended RAID presets for different drive classes are:
SSD Easy Tier preset for solid-state drives
Basic RAID 5 for SAS drives
Basic RAID 6 for Nearline SAS drives
Using the recommended configuration, spare drives are also automatically created to meet
the spare goals according to the preset chosen; one spare drive is created out of every 24
disk drives of the same drive class on a single chain.
For example, if you have 20 x 450 GB 10 K SAS drives on one chain, one drive in these 20
drives is dedicated as a spare drive. If you have 20 x 450 GB 10 K SAS drives on both chains,
which means that there are 10 drives in each chain, then one spare drive on each chain is
created. So, if you have 40 x 450 GB 10k SAS drives on both chains, then two spare drives on
each chain are created and you have a total of 36 drives that can be array members for the
RAID setup.
Spare drives in the IBM Flex System V7000 Storage Node are
global spares, which means
that any spare drive having at least the same capacity as the drive that needs to be replaced
can be used in any array. Thus, an SSD array with no SSD spare available would use an HDD
spare instead.
In our example above using the recommended configuration the Wizard propose to build
three arrays using the Basic RAID 5 for the 146GB drives (discovered as 136,23GB) and one
basic RAID 5 for the 300GB drives (discovered as 278,90GB). If the proposed configuration
meets your requirements, click Finish, and the system automatically creates the array
MDisks with a size according to the chosen RAID level. For each of the two different drive
types a disk is assigned as hot spare.
Storage pools are also automatically created to contain the MDisks with similar performance
characteristics, including the consideration of RAID level, number of member drives, drive
class, and so on.