Adjusting scans to improve computer performance

Article:HOWTO55250  |  Created: 2011-06-29  |  Updated: 2011-12-16  |  Article URL
Article Type
How To


Adjusting scans to improve computer performance

By default, virus and spyware scans to minimize the effect on your client computers' resources. You can change some scan settings to optimize the performance even more. Many of the tasks that are suggested here are useful in the environments that run Symantec Endpoint Protection in guest operating systems on virtual machines (VMs).

The settings that are available are different for Windows computers and Mac computers.

See Managing scans on client computers

Table: Adjusting scans to improve performance on Windows computers



Modify tuning and compressed files options for scheduled and on-demand scans

You can adjust the following options for scheduled and on-demand scans:

  • Change tuning options

    You can change the scan tuning to Best Application Performance. When you configure a scan with this setting, scans can start but they only run when the client computer is idle. If you configure an Active Scan to run when new definitions arrive, the scan might not run for up to 15 minutes if the user is using the computer.

  • Change the number of levels to scan compressed files

    The default level is 3. You might want to change the level to 1 or 2 to reduce scan time.

See Customizing administrator-defined scans for clients that run on Windows computers.

Use resumable scans

For computers in your network that have large volumes, scheduled scans can be configured as resumable scans.

A scan duration option provides a specified period to run a scan. If the scan does not complete by the end of the specified duration, it resumes when the next scheduled scan period occurs. The scan resumes at the place where it stopped until the entire volume is scanned. Typically you use the scan duration option on servers.


Do not use a resumable scan if you suspect that the computer is infected. You should perform a full scan that runs until it scans the entire computer. You should also not use a resumable scan if a scan can complete before the specified interval.

See Setting up scheduled scans that run on Windows computers.

Adjust Auto-Protect settings

You can adjust some settings for Auto-Protect scans of the file system that might improve your client computers' performance.

You can set the following options:

  • File cache

    Make sure the file cache is enabled (the default is enabled). When the file cache is enabled, Auto-Protect remembers clean files that it scanned and does not rescan them.

  • Network settings

    When Auto-Protect scans on remote computers is enabled, make sure that Only when files are executed is enabled.

See Customizing Auto-Protect for Windows clients.

Allow all scans to skip trusted files

Virus and spyware scans include an option called Insight that skips trusted files. By default Insight is enabled. You can change the level of trust for the types of files that scans skip:

  • Symantec and Community Trusted

    This level skips files that are trusted by Symantec and the Symantec Community.

  • Symantec Trusted

    This level skips only files that are trusted by Symantec.

See Modifying global scan settings for Windows clients.

Randomize scheduled scans

In virtualized environments, where multiple virtual machines (VMs) are deployed, simultaneous scans create resource problems. For example, a single server might run 100 or more VMs. Simultaneous scans on those VMs drain resources on the server.

You can randomize scans to limit the impact on your server.

See Randomizing scans to improve computer performance in virtualized environments.

Use Shared Insight Cache in virtualized environments

Shared Insight Cache eliminates the need to rescan the files that Symantec Endpoint Protection has determined are clean. You can used Shared Insight Cache for scheduled and manual scans on your clients computers. Shared Insight Cache is a separate application that you install on a server or in a virtual environment.

See Configuring your clients to communicate with Shared Insight Cache

Table: Adjusting scans to improve performance on Mac computers



Adjust scan priority

Applies to scheduled scans on clients that run on Mac computers.

Scan priority on Mac computers is equivalent to tuning or performance adjustment on Windows computers. High priority means that the scan runs as fast as possible, but other applications may run more slowly during the scan. Low priority means that other applications run as fast as possible, but the scan may run more slowly. Medium priority balances the speed at which applications and scans run.

See Customizing administrator-defined scans for clients that run on Mac computers.

Modify compressed files setting

Applies to Auto-Protect and on-demand scans.

You can enable or disable the option, but you cannot specify the level of compressed files to scan.

See About commands you can run on client computers.

Legacy ID


Article URL

Terms of use for this information are found in Legal Notices