Loaded plugins: fastestmirror
rpmdb: mmap: No such device
error: db4 error(19) from dbenv->open: No such device
error: cannot open Packages index using db3 - No such device (19)
error: cannot open Packages database in /var/lib/rpm
Traceback (most recent call last):
  File "/usr/bin/yum", line 29, in ?
    yummain.user_main(sys.argv[1:], exit_code=True)
  File "/usr/share/yum-cli/yummain.py", line 229, in user_main
    errcode = main(args)
  File "/usr/share/yum-cli/yummain.py", line 84, in main
    base.getOptionsConfig(args)
  File "/usr/share/yum-cli/cli.py", line 184, in getOptionsConfig
    enabled_plugins=self.optparser._splitArg(opts.enableplugins))
  File "/usr/lib/python2.4/site-packages/yum/__init__.py", line 191, in _getConfig
    self._conf = config.readMainConfig(startupconf)
  File "/usr/lib/python2.4/site-packages/yum/config.py", line 754, in readMainConfig
    yumvars['releasever'] = _getsysver(startupconf.installroot, startupconf.distroverpkg)
  File "/usr/lib/python2.4/site-packages/yum/config.py", line 824, in _getsysver
    idx = ts.dbMatch('provides', distroverpkg)
TypeError: rpmdb open failed
 

I tried running the rpm rebuilddb but it won't work:

rpm --rebuilddb
rpmdb: mmap: No such device
error: db4 error(19) from dbenv->open: No such device
error: cannot open Packages index using db3 - No such device (19)