Slow recovery

Tips to improve slow data recovery

Data recovery is concerned with accessing data first, and speed is taken as a secondary consideration. CnW is always looking at ways to improve speed, but a higher consideration is always the ability to recover files from very corrupted media. Over the years disk drives have kept increasing in size. In 2004 a typical PC drive was 40GB (IDE). It is now atleast 256GB for an SSD drive and a few TB for a rotating drive. Transfer speeds have not kept up with disk sizes, so jobs all take longer.

There are several points that assist with reducing the time to perform recovery, and these are listed below.

External USB Drive
The external USB drive is a very useful means to store recovered files and disk images on. The drive can be plugged into a PC and detected automatically. The default Windows mode with external drives is to optimise for quick removal. This means that the operating system caching is not enabled. For memory sticks, where the disk is often plugged in and out, this is often the best setting, but for a large USB drive, the effect on performance is rather dramatic. If the drive is set for optmising performance, files written from a recovered disk may be 10 times faster.

To set up this mode it is necessary to go to Drive properties, and Polices, and set for ‘Optimize performance’ Sometimes it will be necessary to reboot the PC. For most jobs, the improvement in speed is well worth while.

Obviously try and avoid USB 2.0. Instead use USB3.0, USB 'C' or eSATA

Disk image

If a disk has many bad sectors, in particular within the directory structure, these sectors may be read many times, and each time the recovery will slow down. The way to overcome this is to create a disk image (once) and work on the image

File Filter
If it is known which files are required, then the file filter can be used to skip unwanted files. For instance it is common for users to want just JPGs and DOC files. The file filter can used so just these files are read, and all other ones are skipped. This can speed up the recovery operation, as well as requiring less space to save the recovered files.