Snapshot

This document is intended to explain what I an trying to do here.

Intention of the project is to record the changed blocks of the disks and build a snapshot from these points.

I have implemented a Device Mapper target and a small driver, tracker driver, which records changed blocks on the disk.

Job of the Device mapper is to send a write request to the tracker driver. Tracker Driver will store the changed blocks. For this tracker will provide an interface to the Device Mapper Target.

Tracker will provide one more ioctl interface for user appliactions to fetch which blocks are changed.

---

| User | | App |

     |                                          --------
     |                                         |  IOCTL |
    \|/                                          --------

---------------- ___ ---------------- | Device Mapper |------------> |Pl |---------->| Target Driver |
| Target | | I | ----------------
---------------- | F | ___

Build process: export TOP_DIR=

1. Go to the Snapshot/Bitmap/bitmapdriver make it will build tracker.ko

2. In Snapshot/Bitmap/dmtarget make It will build a interceptor.ko

3. Snapshot/Bitmap/Test Run the script : dmsetup_remove.sh It will load modules and create a device mapper target.