A data set may have been migrated or archived by storing it out of the normal data file system to a tape or some other storage medium. Such data sets will have a volume serial number set to a pseudo-value that indicates that they are not available on an online volume. Data facility hierarchical storage manager (DFHSM) uses the special volume serial number MIGRAT for this purpose. The SFTP subsystem recognizes this by default and issues the appropriate allocation request to cause such data sets to be recalled when asked to do so.

Various other storage management systems use different values as the pseudo volume serial number for data sets they have migrated. You can give any such special volume serial number via the environment variable SSH_SFT_PSEUDOVOLUME_VOLSERS, which accepts a comma-separated list of one or more volume serial numbers, matching those in use by the local site storage manager to denote migrated data sets. In the case where migrated data sets at your installation have volume serial numbers other than MIGRAT, you can specify this environment variable in your shell profile or STDENV DD. See Tectia Server for IBM z/OS Administrator Manual for further details.

Extended file attributes automount and autorecall are used to control the behavior of SFTP when working with migrated data sets. See Controlling File Transfer for further details. Note that the requisite security manager permissions may be required to recall data sets.