For most users, their Internet upload speed is not as fast as the local area network speed. So one can copy files to the CacheDrive faster than the upload from the CacheDrive to the cloud. If the copy size is larger than the available cache size, the user may receive an alert email saying disk space is nearly full. When the cache is full, i.e., no more cache space available, files won't be able to be copied to the CacheDrive. However, as files continue to be uploaded to the cloud, cache space will increase over time. 

It is recommended to get a CacheDrive with sufficient cache size for regular bulk copy operations to avoid unnecessary cache swapping. Current CacheDrive sizes range for 1 to 32TB for physical gateways (G80, T600, R1100) or 1 to 100TB for virtual machine gateways. 

** Available cache size means 'Total Cache' minus 'Files to be Uploaded'. CacheDrive will swap out the files that have already been uploaded to the cloud to make room for newly copied files. Swap-out means file contents are vacated while file metadata is kept on the CacheDrive. Master copies of the file contents are always kept in the cloud. 

** We currently don't support dynamic disk expansion for either physical or virtual gateways. In other words, cache sizes should be determined when ordering physical gateways or when building virtual machines.