Backups are currently housed under /erdos/backups, followed by a hostname directory, then a user directory.
For example, here are some backups of Postgres databases on wright:
/erdos/backups
└── wright
└── postgres
├── beanmine-dev.dat
├── biotestmine.dat
├── chickpeamine-dev.dat
├── cowpeamine-dev.dat
├── gcv_glycine.dat
├── userprofile-soymine-dev.dat
└── userprofile-soymine-save.dat
The deepest directory (postgres in this case) should be owned by that user. Above that, ownership is root.