Disk Space
Files encrypted with AES-CBC-CS1 keys consume additional disk space in contrast to files encrypted with AES-CBC keys. This is because AES-CBC-CS1 encryption requires file IVs to be created and persistently stored in contrast to AES-CBC encryption which does not consume any additional disk storage.
Therefore, administrators need to plan and provision additional disk capacity prior to deploying AES-CBC-CS1 encryption.
| AES-CBC | AES-CBC-CS1 | |
|---|---|---|
| Local Linux (CTE) | No change to file size. No extended attribute allocation | Internal use of extended attribute per file. Extra 4KB increase in file size. |
| Local Linux (CTE-U) | Internal use of extended attribute per file. Extra 4KB increase in file size. | Internal use of extended attribute per file. Extra 4KB increase in file size. |
| Remote Linux (CTE) | No change to file size. No extended attribute allocation | Extra 4KB allocation in the form of an embedded header per file. With CTE guarding enabled, file size expansion is hidden. |
| Remote Linux (CTE-U) | Internal use of extended attribute per file. Extra 4KB increase in file size. | Internal use of extended attribute per file. Extra 4KB increase in file size. |
