Can I use a multi-disk eSATA enclosure with RAID?
Yes. That said, be aware that the TivoHD, TivoHD XL, and TiVo Series3 support a maximum internal+external capacity of 2.2 TB (2.0 TiB). With the latest tools, the maximum capacity allowed for a single TiVo drive is 1.1 TB (1.0 TiB) plus the capacity of the original drive. RAID will not change that. Keep in mind that only the discontinued TiVo Series3 (TCD648250B) allows you to use the external drive of your choice without opening the unit and voiding the warranty. The TivoHD (TCD652160) and TivoHD XL (TCD658000) both require you to open the unit and void the warranty if you want to use something other than the 500GB Western Digital My DVR Expander.