Filter
Top Products
Chapter 10. The DS Storage Manager - logical configuration 193
Figure 10-2 An extent pool containing 2 volumes
Figure 10-2 is an example of one extent pool composed of ranks formatted for FB data. Two
logical volumes are defined (volumes 2310 and 7501). Each volume is made up of 6 extents
at 1 GB each. This makes each volume 6 GBs. The numbering sequence of LUN id 2310,
shown in the diagram as the top volume, translates into an address. The volume identification
number is built using the following rules: xyzz, x = the LSS address group, xy = LSS number
itself, and zz = the volume id(volid). For example, LUN 2310 has an address group number of
2, is located in LSS 23, and has a volid of 10.
Different volumes on a single extent pool can be assigned to the same or different LSSs.
Extent pools are assigned to server 0 and server 1 during configuration and receive their
server affinity at this time. If you are using the custom configuration, we recommend, for user
manageability reasons, that you associate the rank even numbers to server 0 and the rank
odd numbers to server 1 when defining the extent pools during the configuration process.
The following rules apply when creating extent pools:
You must configure a minimum of two extent pools to utilize server 0 and server 1.
More than one rank can reside in an extent pool, but you cannot make two extent pools out
of only one rank. We recommend that you create one extent pool out of one rank, unless
the LUN capacity is greater than the capacity of one rank in the extent pool.
Some general considerations are:
One rank per pool will not constrain addresses.
Ranks can be added to an extent pool at any time.
The logical volumes defined in one extent pool can be in different LSSs.
The logical volumes in different extent pools can be in the same LSS; they are limited only
by the odd and even server affinity.
Ranks can be removed from an extent pool if no extents on the rank are currently
assigned to the logical volumes.
Any extent can be used to make a logical volume.
2
3
1
0
7
5
0
1
Extent Pool
1GB Extents
Ranks formated for FB data