sybase:CREATE or ALTER DATABASE failed because the device 'default' has no space available either for log or for data.

When this error start showing you that means you don't have space to be utilized by DB for data storage or even for log purpose. so you can't alter database size.

You need to initialize some spare disk.

i.e.

1> disk init name=sybase_disk,physname="D:\sybase_test_database\data\sybase.dat",skip_alloc="true",size="10G"