处理时遇到错误:libapache2-mod-php5 php5 php5-cli

我现在正在使用Ubuntu 11.10。当我努力通过键入来安装 php5 时

sudo apt-get install php5

我收到此错误：

......
Errors were encountered while processing:
 libapache2-mod-php5
 php5
 php5-cli
E: Sub-process /usr/bin/dpkg returned an error code (1)

我尝试再次执行此操作，但只是遇到了相同的错误。然后有人建议我删除它。我做了：

sudo apt-get remove --purge php5

并得到此错误：

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED:
  php5*
0 upgraded, 0 newly installed, 1 to remove and 27 not upgraded.
3 not fully installed or removed.
After this operation, 20.5 kB disk space will be freed.
Do you want to continue [Y/n]? y
(Reading database ... 
dpkg: warning: files list file for package `firefox-locale-en' missing, assuming package has no files currently installed.
(Reading database ... 161883 files and directories currently installed.)
Removing php5 ...
Setting up libapache2-mod-php5 (5.3.6-13ubuntu3.8) ...
cp: reading `/var/lib/ucf/hashfile.5': Input/output error
dpkg: error processing libapache2-mod-php5 (--configure):
 subprocess installed post-installation script returned error exit status 1
Setting up php5-cli (5.3.6-13ubuntu3.8) ...
cp: reading `/var/lib/ucf/hashfile.5': Input/output error
dpkg: error processing php5-cli (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 libapache2-mod-php5
 php5-cli

然后我尝试只安装 php5-cli 并收到此错误：

Reading package lists... Done
Building dependency tree       
Reading state information... Done
php5-cli is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 27 not upgraded.
3 not fully installed or removed.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]? y
Setting up libapache2-mod-php5 (5.3.6-13ubuntu3.8) ...
cp: reading `/var/lib/ucf/hashfile.5': Input/output error
dpkg: error processing libapache2-mod-php5 (--configure):
 subprocess installed post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of php5:
 php5 depends on libapache2-mod-php5 (>= 5.3.6-13ubuntu3.8) | libapache2-mod-php5filter (>= 5.3.6-13ubuntu3.8) | php5-cgi (>= 5.3.6-13ubuntu3.8) | php5-fpm (>= 5.3.6-13ubuntu3.8); however:
  Package libapache2-mod-php5 is not configured yet.
  Package libapache2-mod-php5filter is not installed.
  Package php5-cgi is not installed.
  Package php5-fpm is not installed.
dpkg: error processing php5 (--configure):
 dependency problems - leaving unconfigured
Setting up php5-cli (5.3.6-13ubuntu3.8) ...
No apport report written because the error message indicates its a followup error from a previous failure.
cp: reading `/var/lib/ucf/hashfile.5': Input/output error
dpkg: error processing php5-cli (--configure):
 subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:
 libapache2-mod-php5
 php5
 php5-cli
E: Sub-process /usr/bin/dpkg returned an error code (1)

我无法打开 php5-cli。出了什么问题，我该怎么办？