Cisco Headend System Release 2.7 Installation Guide
Appendix D
Storage Requirements
Storage Requirements
42
Sizing Backup Storage Requirements
A formula that can be used to calculate how much disk space is needed for storing
backups is as follows:
Required Total Storage = [(size of Informix database backup + size of key files backup) *
number of copies + (size of file system dumps) * number of copies] * growth factor
backups is as follows:
Required Total Storage = [(size of Informix database backup + size of key files backup) *
number of copies + (size of file system dumps) * number of copies] * growth factor
The size of each backup type can be obtained as follows:
Size of Informix Database Backup
The ‘onstat -d’ command reports disk space allocated in the Informix database. The
number of bytes used in the database is not readily apparent and a little math is
needed to calculate it.
1 Obtain the pages in use in each DBspace by subtracting the ‘free’ column from
The ‘onstat -d’ command reports disk space allocated in the Informix database. The
number of bytes used in the database is not readily apparent and a little math is
needed to calculate it.
1 Obtain the pages in use in each DBspace by subtracting the ‘free’ column from
the ‘size’ column.
2 Add up all the pages in use.
3 Multiply the total pages in use by the page size (2K) of the DBspaces.
Example:
3 Multiply the total pages in use by the page size (2K) of the DBspaces.
Example:
# onstat -d
IBM Informix Dynamic Server Version 11.70.FC4 -- On-Line -- Up 16:47:08 --
7759872 Kbytes
Dbspaces
address number flags fchunk nchunks pgsize flags
owner name
27984b028 1 0x40001 1 1 2048 N BA
informix rootdbs
283993028 2 0x40001 2 1 2048 N B
informix physdbs
2839931d0 3 0x40001 3 1 2048 N B
informix logspace
283993378 4 0x42001 4 1 2048 N TBA
informix tempspace1
283993520 5 0x48001 5 1 2048 N SBA
informix sbspace1
2839936c8 6 0x40001 6 1 2048 N BA
informix dataspace1
283993870 7 0x40001 7 1 2048 N BA
informix dataspace2
7 active, 2047 maximum