WholesaleBackup clients use a local cache to perform operations. This note provides information on cache utilization and management in both our new client as well as our original client.
The WholesaleBackup backup client uses a folder as a temporary working space while operations are running and it releases this space when operations complete.
This folder is used as scratch space when a backup or restore is running. For example, during a backup of a file, the client needs a location to encrypt the file and to compress the encrypted version, so space will be temporarily needed for two copies of the file. If the file is a Microsoft Exchange EDB file, then it will be placed temporarily in that folder so eseutil can be run on it to verify it, resulting in the original plus encrypted plus compressed copies of the .EDB file being temporarily in that folder, so in this case space for 3X the size of the .EDB file is required. Now remember that backups (and restores) are run in parallel, so multiple files maybe processed at any given time. So you can see it is difficult to estimate exactly how much free space is required as it is totally dependent on what the data the client is backing up and how many files are being processed in parallel. Recognizing this, we have put in a check to be sure the client does not fill up the volume the temporary work folder (aka cache) is on, and in fact, the client uses this same setting to protect all volumes the client writes to. As shown below you have the option of how much space to keep free on each volume (please see the second screen capture below for the default value).
This screen capture shows where the folder is specified under the Backup>Settings tab.
This screen capture show to specify the minimum free disk space which the client will preserve on any volume that the client is writing data, this is accessed opening the client in -expert mode.
Please note that this folder is also used to download backup history when you are doing a restore from computer's other than the local one you are backing up from, and that data is preserved between client operations, so in fact it's not temporary, but it is usually pretty small.