Open File Copy - Options

This feature is only available with Double Image-O.

The Open File Copy options relate to copying open files  (files that are open by the operating system or an application, otherwise considered 'in-use'). The 'Open File Copy' selection can be turned off or on.  When set on, the remaining options take effect, as describe below.

If you are not familiar with copying open files and why this feature is needed you may want to read the description.

 

Open File Copy Options - Default

 

Copy open files - is an on/off setting. When checked, Double Image-O will copy open files on the local drives that have been selected. The default setting is all disk drives on the local machine that Double Image-O is running on and drives, folders and files that have been selected in the Backup Tree.

 

Open files and dynamic disks are copied from the computer that Double Image-O is installed on.  If open files are to be copied from a remote computer, then Double Image-O needs to be installed on the remote computer.

The Target drive/folder may reside on a local computer or a networked computer.

Use default settings - when set, the default settings are used as defined by Double Image-O internally. The default settings can be overridden by selecting 'Specify settings manually'. When you first select the default settings the defaults are shown to the user. The Cache file size in MB will show 0 (zero), since the default value is calculated at backup time.
Specify settings manually - select this setting to have the following options override the default 'copy open files' settings.
 
 

Open File Copy Options - user settings

Quiet time wait period, in seconds
The default is 3 seconds.

The technical term for this is a quiescent wait period which permits the copy open file driver to create a cache and to ensure that all open files have been quiet for this length of time. Normally 3 seconds will be sufficient for any open files.

When a Double Image-O copy session is started you will usually see a wait period that can be up to 30 seconds - the reason is that Double Image-O is creating a cache to deal with the open file writes that occur during the backup session, then the quiet time wait is applied.
Some programs do not permit a quiet period.

The list of programs that do frequent writes to disk, without providing a sufficient quiet period, are listed below.

A work around is to Pause this software until the 'wait for quiet period' is completed. Once the backup progress meter begins to show activity the 'wait for quiet period' the snapshot is complete and the applications mentioned below may be started.  Not all programs are listed below, but will be added to as we learn of them. These applications only cause an effect if they are writing to the Double Image Source drive.

Quiet time wait time out in minutes
The default is 30 minutes. This time is the maximum time Double Image-O will wait for the quiet time, above, to have occurred. If no period of 3 seconds (default) occurs and this amount of time (in minutes) is passed, then the backup attempt is stopped.
 
Under which conditions could this occur? - when an application or server program has open files that are being  written to without allowing 3 seconds of file write inactivity.
Cache file size in MB

The default cache file size is 2% for each volume that has folders or files being backed up. The minimum size of the Cache is 20MB and the maximum size of the Cache is ~7GB. This maximum limit value is only relative to the changed sector/blocks occurring throughout the backup session. You could have a file that is 30MB in size, but if only one record is changed within the file, then most likely only a few sector/blocks are added to the Cache.

First, the cache is used by Double Image-O to hold only changed blocks/sectors of data during the backup process. This can make the cache size rather small in most cases. If you have a system that has extremely large amounts of I/O during the backup process, then it may be necessary to increase the cache size, by changing the Open File Copy options manual settings.

If, for example, you selected drives C and D in the Double Image-O backup tree with a combined usage of 20GB, then the cache size would be 1.5% of 20GB.

This limit value is only relative to the changed sector/blocks occurring throughout the backup session. A files being backed up can be very large in size, but if only 1 record is changed within the file, then most likely only one or two sectors are added to the Cache, therefore the size of the files being backed up are not relative to the smaller sized Cache.

If you set this value to a number greater than 0 (zero) then Double Image-O will use the manually set value for the Cache size.  If you leave the Cache file size showing 0 (zero), then the value is calculated by Double Image-O at the beginning of the backup process.

Cache file location

The default cache file location is on the same drive that the Windows system drive is on and located in <system drive>\Documents and Settings\<your username\Local Settings\Temp.

You may change the cache location to another drive or folder. It may be helpful to have the cache on an independent drive to gain a little more throughput (speed).

Default Example

C:\Documents and Settings\Art Rivers\Local Settings\Temp

 

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