Reagarding use of OJS with existing system

I am using own website for journal. Now I want to switch it into OJS. I have one question regarding this:
Can I use OJS for my new issues(Under the same Domain), and the previous issues on the previous webpages ? So that I can preserve my Links that has already been created.

You can put that galleys can be downloadable from other link than OJS. Is that what you ask?

Actually I am using my own website to receive submissions, publish volume and issues.
Now I want to shift to OJS for submissions , issues everything.

Is this possible to start with OJS (with a new link on the same domain)and the previous volumes and issues remain on the previous links?

Lets say I have published 2 volumes on my website and now want to start OJS from volume 3. Will these two things simultaneously work?

you can use scenarion like this
http://mypreviousjournal.org/ojsname
and put all articles there and link them to
http://mypreviousjournalsite.org
You can start new in your OJS.
But, at some point if you want to migrate your old files and sytsem you should enter them into OJS.
My suggestion is that you shall put everything in OJS. I have done that several times even with journals when they do have more than 2500 articles in archive.

Ok, that means I can run OJS for my new articles, and migrate the older later on. Right??
I hope google will not mind it for indexing…

Yes, you can later add issues that are previously published. I created archives of previous 45 years of one journal.
My suggestion is to rethink your concept and think again what you really want to achieve and then check whether you want previous issues add now or later.

For example, you can install OJS in
http://myjournal.org/ojs
and put new issues and add old one too and when you finish move it to domain
http://myjournal.org
and that is it.