That was clear enough so I went to google's Webmaster Tools, put the link and it worked!
Whoa! So easy, so quick, so issue free. I tried a different extension before, it crashed my site for a while so now I was wary what this one could do, but this time all went perfectly. No complains.
I used standard settings and after few minutes I got "Internal Server Error" page. When I checked my CPU usage on a hosting server, it reached quickly max allowed limit, hold for a while, then goes to zero and then up again. So far I noticed, it looks like crash because of lack of CPU power.
So I tried again but with lower settings "Max parallel connections" from 50 to 30 (I know it's about RAM not CPU but thought that with less connection CPU will be not so overwhelmed), result the same, too hight CPU usage, everything crashes for a while, the same CPU usage pattern.
Again I lowered settings. This time: priority to 0.3, Max parallel connections to 5. Result: an error site with: "Fatal error: Cannot pass parameter 2 by reference in /home/xxxxx/public_html/administrator/components/com_jcrawler/admin.jcrawler.php on line 189. CPU usage again hits maximum and crashes. Memory usage is ok, far from reaching limits.
I checked FTP and did find sitemap.xml but given above, I don't trust it is done well or till the end.
I have a payable hosting account and it suppose to be one of the best in given area, yet it can't handle JCrawler. So either hosting is overrated or JCrawler simply works poorly.
Thanks, but I am deinstalling JCrawler, doesn't work for me :(.