What should I do if my backup script using HSI works sometimes but often fails?

If your backup script using HSI sometimes works but often fails, make sure you are using the correct class of service (COS) while putting files into Indiana University's Massive Data Storage Service (MDSS). This is especially important if you are doing backups using a command-line pipe into HSI. Since in this case the amount of data is unknown to MDSS beforehand, the service cannot choose the correct COS automatically and you must specify it, depending on the file size. For backups larger than 64MB, specify COS 3, using cos=3 in HSI. In HSI, you can use the lscos command to show the available classes of service.