DISAM error 27 indicates that a specific file has reached a system limit of a file size. This error can occur on any machine that hosts the Attunity Staging area (which uses some kind of ISAM files) of a CDC solution.
The limit for a file size is defined in a parameter named fsize in the system limits file. For example, on AIX machine this is typically in /etc/security/limits. To overcome the problem there is a need to increase the value of the parameter or to set it to -1 which indicates no limit.