Dear Adarsh,
In your case you don't have to increase anything.
By default i guess your MIP_log_001 would be 10GB until unless you have opted for thoer values during installation.
Regarding frequency of Log backup, it purely depends on the system transactions.
15minutes transactional backup....That not true.
Perform following steps:-
Create two folders in E:Sybase/SID
1.Backups
2.log_archives
Goto E:/sybase/SID
execute---> SYBASE.BAT
isql -S<SID> -Usapsa -P<Password> -X
1> use master
2> go
1> sp_config_dump @config_name='<SID>DB',
2> @stripe_dir = 'E:\sybase\<SID>\Backups' ,
3> @compression = '101' ,
4> @verify = 'header'
5> go
1> sp_config_dump @config_name='<SID>LOG',
2> @stripe_dir = 'E:\sybase\<SID>\log_archives' ,
3> @compression = '101' ,
4> @verify = 'header'
5> go
For taking Full backup
isql -S<SID> -Usapsa -P<Password> -X
1> use master
2> go
1>dump database <SID> using config = '<SID>DB'
2>go
Similarly taking trasactional Backup
1> use master
2> go
1>dump transaction <SID> using config = '<SID>LOG'
2>go
Regards
Anand