Just a brief about myself and my requirements.
I am a Web Application Developer and possess basic skills in LINUX and building PCs.
Recently our Buffalo NAS 8TB configured in Raid 5 crashed. It would not start and neither did the recovery work. After a bit of digging I deduced that the RAID was corrupted and in order to even think about a recovery i would have to take individual copies of each 2TB drive.
We eventually got our data recovered but at a price.
We store a lot of critical data on the HD namely 4K videos and large audio files from our production house. More precisely once the projects are completed the Final Cut is stored on this server.
Now we would like to build our own NAS and in such a configuration that we have a back up always present.
Presently we have 4x2TB and 2x3TB drives.
I believe Raid 1 (mirror) would provide this functionality what I would like to know is
1) How many drives can i install into this system? (including the drives for mirror)
2) What is the system configuration needed to support this plan?
RAID 1 mirror is a very good way for protecting your data, you can pretty much install as much drives as you need, depending on what time of RAID system
you're going to use. On board RAID with your motherboard will support as many drives it offers in the SATA ports, so if you have 6 ports on your motherboard then you will be able to have 6 drives available to be put in RAID of your choice, however an external RAID card is a better choice - it's a lot more expensive but usually offers better speeds, better reliability compared to motherboard inbuilt RAID controllers and allows you to connect more drives depending on the card you have.
The benefit of an external card is, if your motherboard crashed or just stuffs up as an example, you can simply just take the RAID card out and put it in another motherboard/computer and have all your DATA still their exactly how it was. Using a motherboard RAID and if i fails all your DATA is still there although you can't use it because in order to put in a new drive to a computer you must always reformat so you would lose your data, unless you can take it to a special data recovery place but it would be very pricy and you would be better of just paying extra for a RAID card.
You can have a good RAID card but all your components need to be fairly good as well. I currently do a lot of video editing myself and I'm building a new system more of a server than A NAS but they can be seen as fairly similar things. You would need good HDD and decent internet connection if you are going to be moving 4k files. FI the Buffalo NAS was good for you building you own system will give you better performance and reliability, I can guarantee that
It was most insightful and answered many of my questions.
You mentioned that Buffalo NAS was good for a system but it is exactly the reason why i am building the NAS. It was configured in RAID5 and the raid got corrupted and it was most difficult to get it fixed and data recovered not to mention it was expensive as well.
I have a few more doubts regarding the specs.
1) Which processor would be optimized for this job?
2) How much DDR3 RAM would i need?
3) I plan to format the 4 x 2TB HDD from the buffalo NAS and use the same in this system and i also have 2 x 3TB WD drives. Is it a good idea to mix drives from different companies?
Do you have a particular budget for building the NAS/Server?
RAID 5 is still a very good raid option.
Usually 4GB memory is common and enough for most people, however I have 8GB ram in my system and
I may upgrade in the future. I'm guessing this is for a company that you work for, you might want to take a look at
ECC memory compared to standard memory as it has "Error Checking". This memory is often used in servers although
memory failures are very rare. 4GB will do although to make it future proof and provide rock solid performance 8GB+ would be good.
Assuming you know, RAM or memory is only needed when the CPU is processing, so if not many calculations are going to be done, it's more dependant
on your HDD, LAN connection.
Since the NAS will be transferring large files, you need to have a pretty good RAID Card, preferably with on-board cache, as
you might seem some with 256, 512mb etc. The RAID card will need to work a lot harder when compared to other RAID'S such as
RAID 1 "mirror"-that is what I use and I find that it does it for me, although RAID 5 is better if you have a good RAID card.
An intel xeon E3 series should do you well, as they're made for servers, you could save a lot of money and get better performance with consumer level
components however, server parts are made for reliability, as you said your RAID 5 got corrupted so have excellent parts will sure be worth the investment.
It's fine to mix drives, are they normal drives . Seagate Barracuda, WD -blue-black-green?
Server HDD are made to transfer files 24/7, so you may want to look at those although they are $$$, however
having RAID normal drives should be fine. If the HDD are from fairly good companies, hitachi, seagate, western digital etc it should be fine
however using the same drive size and manufacturer is usually recommended. I personally have different drives, and it all works fine.
WD Green drives are known to "fall out" or not able to becoming detected in RAID arrays.
Buffalo NAS and other NAS, are usually cheaper and often do a fairly good job, but buying/building actual NAS/Server will generally provide
better redundancy and reliability, it's going to cost more although the most important thing is the data so it's worth spending.