HP XP7 Storage - Manual (Page 68)

1. For Base Secondary Volume, select the initial S-VOL’s CU number and LDEV number. If
you are selecting only one P-VOL, this LDEV is the secondary volume. If you select multiple
P-VOLs for pairing, this LDEV is the base S-VOL that is assigned to the first P-VOL and
from which subsequent S-VOL LDEVs are assigned to the list of P-VOLs.
CAUTION: In XP24000/XP20000 Disk Array and P9500, LUN IDs display in
hexadecimal numbers. In XP7, LUN IDs display in decimal or hexadecimal numbers. If
you have selected the decimal notation, when assigning an S-VOL in a XP24000/XP20000
Disk Array or P9500 storage system, make sure to convert the hexadecimal LUN ID
number to decimal.
2. For Selection Type, select the method for assigning S-VOLs when multiple primary volumes
are selected.
- With Interval, specify an interval the system skips between secondary system LDEV
numbers.
3. - With Relative Primary Volume, the system assigns secondary system LDEV numbers
based on proximity to P-VOL LDEV numbers.
8. Click Options to define the following optional settings:
1.
For Primary Volume Fence Level, specify whether the primary system allows or rejects
write operations to the P-VOL when the pair is split due to an error.
- Data: The P-VOL cannot be written to.
- Status: The P-VOL can be written to if the primary system can change S-VOL status to
Suspended; otherwise cannot be written to.
- Never: The P-VOL can always be written to.
2. For Initial Copy Type, specify whether to copy data from P-VOL to S-VOL during the
operation.
- Entire Volume creates the pair and copies data to the S-VOL. (Default)
- None creates the pair but data is not copied to the S-VOL. This requires that data in the
P-VOL and S-VOL are already identical.
3. For Copy Pace, specify the number of tracks to be copied per remote I/O during the
operation. Options are 3 or 15; 15 is the default. This option affects performance as
follows:
3 is slow, improves performance and lowers impact to host I/O.
15 is fast, may lower performance and increase impact to host I/O.
4. For Initial Copy Priority, specify the scheduling order for the initial copy operation. The
range is 1 to 256; 32 is the default.
If a time-out error occurs during this operation, the order specified in Initial Copy Priority
may not run as expected. A time-out error can occur because of the CU configuration or
data path error. Review the error, delete the pair with an error, then retry the operation.
5. For CFW Data, specify whether CFW (DASD fast write) data is copied to the S-VOL.
- Primary Volume Only: CFW data is not copied to the S-VOL.
- Secondary Volume Copy: CFW data is copied to the S-VOL.
6. For DFW to Secondary Volume, specify whether the primary system splits the pair in the
event that the secondary system cannot copy DFW data to the S-VOL.
- Require: The pair is split.
- Not Require: The pair is not split.
The interaction of DFW required and the P-VOL fence level setting can cause a host
application to fail with a permanent I/O error when attempting to update an P-VOL. Keep
68 Cnt Ac-S Z pair operations