Overview
Sometimes it may take a bit longer than you would expect to restore a file from a backup set on the CrashPlan app. This article explains the steps the CrashPlan app takes to restore a file to a your device, external factors impacting network speeds that are outside CrashPlan's control, and tips for improving file restore speeds.
File restore process
To restore a file, the CrashPlan app:
- Accesses the archive index to locate the blocks of data that make up the file you want to restore.
- Reassembles the relevant blocks to recreate the file.
- Retrieves the file and downloads it to your device.
- Decompresses and decrypts the file back to its original state.
Because these steps reduce the amount of data to transfer while keeping files secure, restoring a file generally takes more time than a simpler file download.
Factors affecting restore speeds
File size and one-at-a-time processing
The CrashPlan app restores and downloads files one-at-a-time, and the size of the files in the queue can slow the restore process. When restoring a large file, the estimated time of completion for that file's restoration can fluctuate and can impact the time it takes to restore multiple files.
If the restoration of a large file is interrupted, the CrashPlan app restarts that restore from the beginning. The CrashPlan app cannot resume a file restore from when the process was interrupted. Preventing the device from entering sleep mode and ensuring a stable network connection helps the restore process for large files complete smoothly and as quickly as possible.
Microsoft Outlook data files
Microsoft Outlook saves your email messages, calendar, tasks, and other items in either an Outlook for Windows Data File (.pst) or an Outlook for Mac Data File (.olm). Because these files are updated throughout the day as you receive emails or schedule meetings, the CrashPlan app backs up Outlook data files using the Volume Shadow Copy Service (VSS) on Windows or an exported .olm file on Mac. In some cases, these files can become quite large. Large Outlook data files or issues encountered during their backup can affect how long it takes to restore such files. For more information, see Restore Microsoft Outlook data using CrashPlan.
Bandwidth and external factors affecting speed
Bandwidth is a measure of theoretical network capacity, but in reality, the actual achieved throughput that any device or application gets will usually differ from this theoretical maximum. The protocols that your devices use to communicate over the Internet take up overhead, bandwidth is shared with other applications, and network latency can slow down connections.
ISPs often provide different amounts of bandwidth for downloads and uploads. The download speed is typically greater than the upload speed. Regardless, it is a good idea to find out from your ISP what level of service you are supposed to be getting, and to then test your service with one of the many ISP speed tests that are freely available on the Internet. Knowing the speed you have been promised by your ISP, and what you are actually receiving, will allow you to verify that you are getting the service you are paying for, and that your backup speeds are not being slowed down by your ISP.
Other facts to keep in mind:
- Backups are an upload operation, because the data is going from your device to the CrashPlan cloud.
- Restores are a download operation, because the data is going from the CrashPlan cloud to your device.
Various factors outside of CrashPlan's control affect your backup and restore speed. The effective transfer rate between your device and our data centers depends on the bandwidth provided by your ISP, as well as network speeds on nodes between your ISP and our data centers. Even if a speed test of your ISP shows that your currently available bandwidth is high, network congestion elsewhere can cause speeds to slow down. The effective network speed between the CrashPlan app and CrashPlan's servers affect the backup and restore speed.
What you can do
- Make sure that you haven't used the network bandwidth settings to limit the transfer rate of the CrashPlan app.
- Make sure that your device is operating optimally, meets our system requirements, and that it has enough RAM and disk space available.
- Networking equipment such as routers, Wi-Fi access points, and firewalls should be functioning optimally. Ensure that your equipment meets system requirements, and try rebooting your router or cable/DSL modem.
- For Outlook data files or other large files, consider creating a backup set with settings optimized for just that file. These optimized settings may help the restore process move more quickly.
- Restore large files in off-hours, when networks are less busy.
- Change the device's power plan to the high-performance mode, or adjust the power settings to enable higher performance. Preventing the OS from putting apps to sleep and allowing it to run at the highest speeds can help restores run without interruption.