I would recommend manaufactures that live and breath storage. I purchase my stuff through a local reseller here in dallas. I've been very happy with the performance and the price is better than what I find online.
The manufactures I use are.
Assuming your using a windows machine for the NVR
I would recommend go with a fiber channel storage ( SAN ) I'm a big fan of block level access to storage pools. iSCSI is good, but is trickier to setup. Plus, I've had issues with some iscsi implementations and software in the past. Fiber Channel has always been straight forward and rock solid.
Your probably not going to run into any IOPS inssues. Each storage bank holds 16 drives, 14 usuable. ( The way I set it up) 7200 rpm drives get about 80 IOPS on the low side. You'll have about 1k IOPS to deal with per 16 drives in Raid 6.
You will run unto a bandwidth issue. Assuming your dealing with H.264 compressed video (if its MJPEG you have a much bigger issue), 80 streams of video, and average bit rate for a 3Megapixel at 20FPS is about 11 MB per/sec, then you will need a bandwith of 880 MB per/sec. Depending on what technology you are using ( NAS, SAS, SAN) , you might have as much as a 10% over head. A safe guess is you'll need a total bandwith of 980 MB per/sec
If your using Fiber Channel, the max write and read spead is about 80% of the channel bandwidth. On you 8 GB fiber channel, that would be 640 MB per/sec. You need 2 x 8GB fiber channel connections to provide enough bandwidth.
If your are trying to connect everything to 1 giant system, your need dual 8GB Fiber Channel. Which also means you'll need an OS that understandands multi-path I/O ( windows 2008 R2, Windows Server 2013, or Windows 8.1). I think largest storage pool you can setup with out purchased insainly priced hardware, is about 1.4 PB. There are other issues also, the best thing is to split the system into smaller junks.
If you dived the the video between 5 NVRs, this is very duable.
Here is how I have Video Production companies setup. The main reason I recommend SAN, is the Raid arrarys are very easy to setup and maintian.Swaping out dead hard drives are quick and painless.
1 x Qlogic ( qlogic is awesome) Fiber Channel Switch $5,000
5 x Single Channel Fiber Channel Card $900 per pc
5 x Tiger Store Install for Shared Storage Access and Storage pools $995 per pc
15 x San Controller with 64TB ( 56 TB in RAID 6 ) can add 3 JBODS $15,000
45 x JOB Expansion 64TB ( 56 TB in RAID 6 ) $7,000
15 x Smart APC Battery Backups $1500 each
Total Bill would be
580K for hardware alone.
Each NVR gets connected to
3 San Controllers. Each San controller is connector to 3 JBODS.
Every 16 Disks I make into a RAID 6 Group. I think that if you expand a raid group beyound 16 disks, you are pushing your luck. I setup email allerts on the SAN, I'm notified if any drives go down, or on any errors.
Each San controller and JBOD takes up 3U of space. Assumming your using 48u cabinets. you'll need 4 Cabinets to hold all this.
I like Tiger Store, becuase you set easly set bandwith limits on each storage pool, and set hard caps on file space allocation. It also makes tape back up easy by allowing shared drive access. If the san was for Database applications, I would take a snap shop of the san then give the tape drive exclusive access to that snap shot for backup. With large amounts of video, your not allowed that luxury. Shared block level Storage is really the easiest way to make a tape backup for video files.
I like the backblase platform allot, but there is a big issue withgetting qualified techs to service it. Swapping out bad drives on a SAN is extremly easy and painless.
You could also off load old footage to an LTO 6 tape. I recommend tandenberg , good tape drives and autoloades.
The Neo400s can store 120TB of uncompressed data. Depending on which backup program you use, it might bring down the storage capacity to 100TB. 14k
Tivoli ( there is better backup software out there) software is about 15k after setup ( based on a previous quote)
I use BRU backup for the Video Production Houses.
Each LTO-6 tape is cost about $70 and holds 2.5 TB of data uncompress.
If you back up all the data using LT0-6, you could store 3PB of data for a cost of 85K per yer.
You could cut the costs of the storage significantly.
Keep 6 months of video on hand. Then back up the rest to LTO-6 Tape. We can divide the cost of the SAN in half.
280k for hardware.
+ 25k for LTO-6 Autoloader with customized back up software and Controller PC
+ 100k a year for new LTO-6 Tapes. ( or you can re-use existing tapes)
I didn't use any systems that that have a higher density than 16 drives per 3u, allot of these require low profile harddrives, or are 2x to 3 x more in cost.
Only use Hitachi or Western Digital Hard Drives.
Back blaze has a great article on drive reliability.