A customer was interested in implementing and using HiDRO's incremental backup output to minidisk feature (DISK to DISK backups) instead of the standard backup output to tape. However, they wanted to alter the provided and documented sample method of using DISK to DISK backups with HIDRO and change it to switch back and forth between just 2 minidisks (491 and 492) instead of using a dedicated minidisk for each weekday of the week (491, 492, 493, 494, and 495).
The customer would then FTP the "dasd tapes" created over to their DR site on a daily basis. The INCREMENTAL backups are based on a BASE backup to physical tape so the current day's INCREMENTAL backup will contain all accumulated changes since the BASE backup and the previous day's INCREMENTAL can therefore be discarded/overwritten.
There are complete instructions in HiDRO's System Administrator's Guide for setting up the DISK to DISK backup process.
The following is what needs to be modified to accommodate this change; running INCREMENTAL backups with a Retention Period of 1 day, each weekday and Saturday, but alternating back and forth between only two backup disks.
In Step 3, make the Retention Period for the Logical Pool you decide to use/create 1 day. If you choose a different Logical Pool name than "DAILY", remember to substitute that name in Steps 6 thru 9 when you copy the sample DISKINCR files for the FileName of your local copies.
In Step 4, define only 2 minidisks, for example 491 and 492.
In Step 6, modify the copied DAILY EXEC as follows to accommodate alternating back and forth between the 491 and 492 each day, and to also include a INCREMENTAL backup on Saturday:
00127 /* generate the correct unit from the day */
00130 when day = 'MONDAY' then unit = '491'
00131 when day = 'TUESDAY' then unit = '492'
00132 when day = 'WEDNESDAY' then unit = '491'
00133 when day = 'THURSDAY' then unit = '492'
00134 when day = 'FRIDAY' then unit = '491'
00135 when day = 'SATURDAY' then unit = '492'
Things to consider:
- The HiDRO 191 minidisk is always included in every backup job generated by SYBMON, consider this when defining the "dasd tape" disks.
- Remember to EXCLUDE the HiDRO minidisks that are "dasd tape" disks being used to hold that backup data.
- Use of an Alternate Command Control File is currently not supported.
- The SM File output from Disk INCREMENTAL backups currently can not be used as input to the INCRGEN Utility. Instead use SYBLIST or CATALOG RESTORE commands to generate restore commands.
- A basic restore command:
R USE ( HIDRO ) U 0492 F SAMMY 0191 TO UNIT 191 USE( SAMMY M ) -
RESTORE from Hidro's 0492 disk and file called SAMMY 0191 to userid SAMMY's 191 disk, erasing any file found in the SAMMY 0191 file if found on SAMMY's 191, then restore that file.