Has anyone performed or use Raspberry Ri for a 24x7x365 day scenario? How does it hold up running all the time?
I have one I've left on all the time for more than a year. It is not super busy (mostly, serves files on a home LAN, logs some sensor data, and keeps an led indicator updated) but it has never been a problem.
Can we something other than an SD card, since I have read SD cards tend to crash
I think it is worth considering that someone who has a SD card related problem is likely to post a question or something somewhere online, whereas someone who does not isn't going to leave a trail of "Hey, my SD card is fine, how's yours?" all over the internet.
By analogy, if you had never owned or used a traditional spinning disk hard drive, you might be inclined to ask, after looking around the web, "Can I use something other than a disk drive, since I have read these tend to break down?". They do indeed tend to break down and anyone who has used one long enough will have seen it happen.
None-the-less, lots of people use lots of spinning disks and most of them are fine most of the time. SD cards do have a limited lifespan, but it is considerable. I've actually put a lot of effort into trying to destroy them to prove this point, and I'm pretty satisfied they are what they appear to be: Like spinning disks, they do not last forever, but they should last for years of reasonably normal use. My 24/7 pi mentioned earlier is still on its first card and I'm not worried about it. Likewise, I have an android phone that's a few years old with an SD card -- probably that gets worked more than the one in the pi -- still fine.
However, I do use an attached usb drive for larger storage. If you are truly paranoid, or there are particular aspects of the filesystem you know get worked a lot, you could move those there. Note that by default raspbian uses RAM for
/run, and swap, so that stuff is okay. The rest of the system doesn't do a lot of writing and if that's all that's up, the card could last longer than you will.