Seems like everything I saw on here was kinda old when it came to HDDs.

I'm using Drive Bender to organize 4 HDDs into a pool that totals 8.6TBs. I have a little over 2TBs left free so wanted to add another drive to the pool to even things out and keep sufficient space open on the other drives.

I have a mix of WD and Seagate drives and both seem to be working fine. I don't have any loyalty to one or the other, but wanted to see what you guys though. Is it worth going with a 6TB drive? I have certain folders backed up/I am covered for a single drive failure, but not sure if 2x3TB drives would be better than 1x6TB. I have plenty of room in my media center case for several more drives, so that's not an issue.

I've seen NAS specific drives, and while my setup isn't really a NAS, would those drives be better/more reliable?

Thanks for your thoughts and feedback!

I manage several SAN's and NAS systems for multiple Small-Medium Business clients. I can say from experience almost all drives manufactured in early and mid 2012 really sucked when it comes to reliability. This was due to the hard drive shortage caused by the flooding in Thailand in late 2011. So i wouldn't buy re-manufactured or used hard drives from this era. However recently, I've been seeing really good reliability from Hitachi drives as well as some newer 4tb HGST Ultrastar drives. HGST is my personal sweet spot that i recommend to clients. Hitachi was bought by WD in 2012 (again due to flooding in Thailand) and is now called HGST. None of my clients use hard drives larger than 4tb at this time. So i cant comment about the reliability of 6tb or 8tb drives currently. Sorry. When it comes to reliability in a bulk storage setup, segate is my worst performer. Not to many WD drives are used by my clients in their storage setups. But I've had great success using them as primary hard drives for their desktop computers. Their Black series kicks ass.

My personal media server uses used enterprise drives that ive recovered from client systems that were going to be retired and crushed. I have a good relationship with my clients and i guaranteed to wipe the drives with DBAN before removing them from their office. All of my bulk storage drives are 2tb Hitachi Ultrastar drives from early 2011. I havent had a single failure out of the 8 original drives in my server since i built it back in Dec 2014. I just added 8 more drives 2 months ago after a HP SAN was decommissioned by a client. These drives currently back up the 8 original drives. I dont have enough content to fill the original 8, so these are just for redundancy purposes at this time. My media server runs 24/7 and gets more data written and read from it than the original SAN's they came from.

Should i use a NAS or storage specific drive? Hell Yes! Use the NAS drive. Great article for comparing the benefits of a NAS drive. Should i use 2x 3tb drives or 1x 6tb drive? Always use multiple drives for greater read and/or write performance. Depends on the RAID level for what performance benefits you'll get. Just never use RAID 0 unless you have a solid backup strategy.

If you have any more questions about storage. Feel free to ask.

i'm looking for a new 4TB HDD,
can anyone help me to find the best one?

i found this article on google
http://www.deskdecode.com/top-best-4tb-hard-disk-drive-monthly-updated/
and they suggest me to buy Seagate Barracuda.
how about that?

Anything BUT Western Digital. I used to be a devout WD fan but in the last 5 years their drives are the worst I've come across. I have 14 drives in my house, 3 of them were WD. Two of them, used for nothing but monthly backups, have failed. My Hitachi and Seagate drives that get used every day live on.

Not normally a Toshiba fan, a IT friend suggested the X300 (6tb) drive was a pretty decent drive for the price. I purchased two for backups at $150 each. Only time will tell though.