HP XP Data Shredder Software - Manual (Page 84)

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The required time shown in Table 22 (page 83) might be as much as four times longer,
depending on the configuration of disk adapter (DKA) pairs.
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When you execute quick formatting at the same time on multiple parity groups that have
different drive capacities, calculate the required time for the parity group that has the largest
capacity.
Host performance might be affected during the execution of quick formatting. Table 23 (page 84)
indicates the estimated performance of a host. However, the values in Table 23 (page 84) might
vary depending on the conditions.
Table 23 Estimated Performance of a Host during Quick Formatting
Performance (%), where 100% Indicates the
Performance when No Quick Formatting is Executed How to Access
80 Random read
20 Random write to the unformatted area
60 Random write to the formatted area
90 Sequential read
90 Sequential write
Creating System Disks
System disks are volumes that are used for the storage system. To execute Quick Format, you must
create the system disk in a free space in a parity group. System disks can be created by performing
either the Install CV operation or the Make Volume operation. For detailed information about these
operations, see
“Creating VLL Volumes (Install CV Function)” (page 71) and “Re-creating the CVs
After Initializing the VDEV (Make Volume Operation)” (page 76) .
The required system disk capacity is as follows:
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Capacity for Quick Format management information: 46 MB, which means 66 cylinders if
the track format is 3380; or NF80, which means 55 cylinders if the track format is 3390.
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Capacity for the audit log buffering area: 130 MB, which means 185 cylinders if the track
format is 3380; or NF80, which means 154 cylinders if the track format is 3390.
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Capacity for additional configuration backup: 7,744 megabytes, which means 9,082 cylinders
if the track format is 3390. The following program products are for the additional configuration
backup function:
◦ XP Business Copy
◦ ShadowImage for Mainframe
◦ XP Auto LUN
◦ HP StorageWorks XP for FlashCopy Mirroring Software
◦ HP StorageWorks XP for FlashCopy Mirroring V2 Software
◦ XP Snapshot
◦ XP Thin Provisioning
To use the Quick Format management information, the audit log, and the Additional configuration
Back up function, you must prepare the system disk with the capacity to store that information in
advance. For example, if two system disks that have 35 MB capacity each are prepared, the
backup copy of the Quick Format management information cannot be made into these system
disks. If the system disk is used for multiple purpose, HP recommends that all necessary capacities
are retained in one volume. For example, to store the Quick Format management information and
84 Performing Virtual LVI/LUN and Volume Shredder Operations