//1.2.3.4/share  /mnt/share  cifs rw,iocharset=utf8,uid=root,gid=root,credentials=/root/smbcredentials   0   0

username=...
password=...

# mount  /mnt/backups
mount: wrong fs type, bad option, bad superblock on //10.13.37.5/backups,
   missing codepage or helper program, or other error
   (for several filesystems (e.g. nfs, cifs) you might
   need a /sbin/mount.<type> helper program)

   In some cases useful info is found in syslog - try
   dmesg | tail or so.
# dmesg | tail
[ 1308.670814] CIFS VFS: No username specified

yum install cifs-utils # centos/redhat/fedora
 apt-get install cifs-utils # debian/ubuntu