Using the Performance Manager GUI 4-11
Hitachi Universal Storage Platform V/VM Hitachi Performance Manager User’s Guide
• In the Monitoring Data area, the list on the upper right of the list
specifies the type of statistics to be displayed in the window. If you want to
view I/O rate, select IOPS (I/Os per second) from the list. If you want to
view transfer rate, select MB/s (megabytes per second) from the list.
• The tree lists parity groups, external volume groups, and V-VOL groups.
Box folders (for example, Box 1, Box E1, Box V1, and Box X1) are
displayed below the storage system folder. The number at the end of a
Box folder name indicates the number at the beginning of parity group ID,
external volume group ID or V-VOL group ID. For example, if you double-
click the Box 1 folder, the tree displays a list of parity groups whose IDs
begin with 1 (for example, 1-1 and 1-2). At the right of each ID, the RAID
level appears. When you select a parity group, the list on the right lists
volumes in the parity group.
The IDs of external volume groups are beginning with the letter "E".
Therefore, a folder whose number is beginning with the letter "E", such as
Box E1, contains external volume groups. For example, if you double-click
the Box E1 folder, the tree displays a list of external volume groups whose
IDs begin with E1 (for example, E1-1 and E1-2). The external volume
groups do not have parity in formation, and no RAID level appears at the
right of IDs.
A volume existing in an external storage system and mapped to a volume
in the USP V/VM storage system by using Universal Volume Manager is
called an external volume. An external volume group is a quantity of
external volumes grouped together for managing and that does not contain
any parity information, unlike a parity group. However, Performance
Management window treats external volume groups same as parity
groups for convenience.
When Copy-on-Write Snapshot is used, the IDs of V-VOL groups begin with
the letter "V". When Dynamic Provisioning is used, the IDs of V-VOL groups
begin with the letter "X". Therefore, if a folder number ends with the letter
"V" or "X", such as Box V1 or Box X1, it contains V-VOL groups.
For example, if you double-click the Box V1 folder, the tree displays V1-1,
which is a V-VOL group ID beginning with V1. If you double-click the Box
V2 folder, the tree displays V2-1, which is a V-VOL group ID beginning
with V2. The V-VOL groups do not have parity information, and no RAID
level appears at the right of IDs.
Unlike a parity group, a V-VOL group is a group of virtual volumes and
does not contain any parity information. However, Performance
Management windows treat V-VOL groups the same as parity groups for
convenience.
The parity group icon ( ) can represent a single parity group. The parity
group icon can also represent two or more parity groups that are
connected together. If two or more parity groups are connected together,
volumes can be striped across two or more drives. Therefore, connected
parity groups provide faster access (particularly, faster sequential access)
to data.