Ubuntu apt-get Installation Software exception

Ubuntu apt-get installation Software exception 1. Ubuntu has the apt-get: Package has no installation candidate exception as follows: # apt-get install <packagename> Reading package lists... doneBuilding dependency tree... donePackage aptitude is not available, but is referred to by another package. this may mean that the package is missing, has been obsoleted, oris only available from another sourceE: Package <packagename> has no installation The solution to candidate is as follows: # apt-get update note: update the synchronization installation list. You may need to add new sources before this step, such as vim/etc/apt/sources. list I added 2 deb http://mirrors.163.com/ubuntu/ hard main universedeb http://tw.archive.ubuntu.com/ubuntu/ hard main universe # apt-get upgrade [upgrade all installable packages? I did not do this step, you can also] # apt-get install <packagename> 2. E: Dynamic MMap ran out of room. please increase the size of APT: Cache-Limit. current value: 25165824. (man 5 apt. conf) the cause of the exception is that the cache is too small. Run the sudo gedit/etc/apt. conf. d/70 debconfgedit command on the terminal. It is a text editing software and can also be used by emacs or other software. In ubuntu10.04, 70 debconf is the cache configuration file. In other linux systems, the configuration file may exist in the./apt directory. Add an APT: Cache-Limit 33554432 line to the open file, and the last quotation mark 33554432 is the Cache size.