I want to build a server hosting about 2TB+ data. Of course SSD is out of the picture in terms of the data drive. My question is: Is there any benefit to use SSDs as the boot drive? I plan to put 16G memory on it. I think most of the time the services should be loaded in memory and the server should rarely require rebooting. In this case, does it make sense to get SSD or just get a RAID1 with two SATA drives?
I don't think so, not at this time. They're expensive, it's a relatively new technology that's not without its own problems; Jeff Atwood has an interesting blog post about the advantages and disadvantages of using them.
Given your intended use case the need for an SSD seems even smaller. You normally see huge benefits when booting and when opening up apps, but on a data server with a lot of RAM that rarely gets rebooted there's no point in spending the extra money.
It depends on the kind of server, but generally speaking, yes, it should be a good idea.
SSD drives are best for read-only data, which is usually what servers are as opposed to workstations. So it has that going for it.
Also, the faster a file can be served, the better the server will be, and since SSD drivers are supposed to be faster, it has that going for it as well.
Finally, SSD drives usually use less power, make less noise, and generate less heat, so the server will require less electricity and cooling (which are the banes of server-rooms the world over), so it has that going for it too.
That said, again it depends on the specifics of your server and case-usage (eg, 16GB sounds good, but will the files be cached in RAM or have to be fetched from disk anyway?), as well as the actual drives in question. Overall however, yes, most servers are generally better off with SSD drives.
With this situation, an SSD boot drive will probably only improve boot time, once everything is started and in RAM (you have 16GB) it won't make any difference. Maybe if you kept a 10GB+ database on it it might help, but probably better to spend the money on more magnetic drives (possibly for redundancy).
I think that's a good idea. The SSD promises greater reliability (especially important for laptops) and improved performance (no relative track-to-track seek time concerns), both of which are wonderful advantages when dealing with server problems.
Do keep in mind, however, that SSD is still very new and not immune to failures of its own. You should research the types of problems people are experiencing with different brands and models of SSD drives before going down this path.
Depends on the server usage, from what you describe probably not worth it. Where SSD's come into thier own is servers with high I/O usage like virtual server hosts.
Stick about 10 virtual machines on a server with standard drives and then compare it to one with SSD's. Get all 10 VM's doing something and watch the SSD based server fly while the old magnectic drive one has stalling VM's as they wait for thier turn to read/write to the HD's.
Back to your original question though, why are you worried about the boot time? Are you planning on regulary rebooting the server? I have servers that haven't been rebooted for about 3 years which I would have thought would be reasonably normal for stable machines that just do the job they were supposed to do.
That's a bad idea. SSD drives give you insane iops, and that's why you pay for them: to hold data that's accessed most frequently in a random fashion. A database on a set of SSD drives can outperform (especially for read-intensive scenarios) a very expensive storage system.
Operating system boots, then practically all executables that are used are kept in RAM, everything unused is put to swap. If you plan for heavy swap use (bad idea) you could put your swap on SSD, but I'd rather use a HDD and put the difference into RAM.
I think it doesn't worth it most of the time.
But if you've got big computing requirements with big files (say Dailymotion / YouTube encoding videos) the read/write speed is probably important.
If your applications are doing a lot of reading, even small files, it can really boost up the performance. However, if you cache the most served data in RAM (See memcached daemon) this is not an issue anymore.