how to backup workspaces in SQL Workbench/J

SQL Workbench/J has a backup mechanism of its own, look at Tools > Options > Backups.

Alternately, in Cygwin:

$ cd $( cygpath -u "$USERPROFILE\\.sqlworkbench" )

$ zip -r ~/tmp/SQLWorkbenchJ_backup_"$( date +%Y%m%d_%H%M )".zip *

$ ls -lrth ~/tmp/SQL*