May i know if its ok to see D under S column when i run top command for checkpoint process?
this has been like this for 1.30hr
That means it is in an uninterruptible sleep, which generally means it is waiting for the disk to do something. If it never leaves this state, it might mean your disk storage is failing. If it rapidly cycles through states, but spends most of its time in D, that might just mean your system is spending a lot of time on disk access, which is not necessarily a problem. But just looking at `top` will have a hard time distinguishing these scenarios.
What do you see if you try to 'strace -ttt -T -p <pid>' the process?
Also, what version is this, and what is the OS flavor and version?