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Multi-pass Imaging


Multi-pass imaging is a process of image creation through several passes (phases). Each phase reads data from different areas of a hard drive, starting from areas with good sectors then going to slow sector areas and finishes with bad sector areas. This approach maximizes the amount of data that can be recovered from a failing drive and reduces it chances to fail during this process.

Phase 1. Copying most good data from the drive

In this phase, R‑Studio reads data from drive by sector blocks, or groups of consecutive drive sectors read in one go. The phase is performed in several steps.

Step 1. R‑Studio reads data from the drive until it runs into a block with bad or slow sector(s). Then it drops that block and jumps to another area until it finds a block with no bad or slow sectors. Then it continues reading data until it runs into another bad or slow block, and the process repeats. When this step is finished, most good data from the hard drive has been read, and R‑Studio has detected the front blocks (edges) of bad and slow sector areas.

Step 2. R‑Studio finds the rear edges of bad sector areas. It reads the skipped area from its rear end backwards until it runs into a block with a bad sector. Then R‑Studio jumps to another bad sector area and the process is going on until all bad sector areas have been processed. When this step is finished, some good data from the hard drive has been read, and R‑Studio has detected the rear edges of bad sector areas.

Step 3. R‑Studio reads data from slow sector areas. It does that much the same way as for bad sector areas.  When this step is finished, good data from slow sectors on the hard drive has been read, and R‑Studio has detected the rear edges of slow sector areas.

Step 4. R‑Studio finds the rear edges of bad sector areas in slow sector areas. When this step is finished, some new good data from slow sectors on the hard drive has been read, and R‑Studio has detected the rear edges of all bad sectors within slow sector areas.

Step 5. R‑Studio tries to read all skipped sector blocks. This is done without skipping bad sector blocks and checking read speed against minimum I/O rate.

When Phase 1 is completed, R‑Studio has read most of readable data and detected front and rear edges of all bad sector areas.

 

R‑Studio tries to read the rest of data in the next phases, and does that sector by sector (rather than blocks).

Phase 2. Trimming

R‑Studio detects the front and rear sectors of bad sector areas. When this step is finished, some new good data from bad sector areas has been read, and R‑Studio has detected the front and rear sectors of all bad sector areas.

Phase 3. Scraping

R‑Studio tries to read data from bad sector areas sector by sector.

Phase 4. Retrying (mostly optional)

R‑Studio tries to read data from bad sectors through several attempts.

 

You may read more about this process in our article Multi-pass imaging in R-Studio

 

Note: Drive scan is disabled during multi-pass imaging,

 

To create an image through multi-pass imaging,

1 Select an object on the R‑Studio 's Drives panel and click the Create Image button

Click to expand/collapse Other ways to create the image

2 Specify image options, a file name, and destination for the image on the Create Image dialog box and click the OK button
Click to enlarge

Create Image dialog box

Click to expand/collapse Bad sectors processing options

> R‑Studio will start creating the image, the Progress message showing the progress.
Click to enlarge

Multi-pass imaging progress dialog box