One way to backup GECAMed databases is to use the pg_dump utility. Until today, we were using the -Ft option to dump into one single tar file which we subsequently compressed with the gzip utility. The current versions of gzip (prior to 1.3) have a filesize limit for the input file of 4 GBytes. Compressing larger files will corrupt the compressed file, making your backup useless. To resolve this issue, I would suggest to use pg_dump's custom file format to dump databases for backup. To do so, replace -Ft option with -Fc option.