Questions[deduplication](server)

I have installed the Data Deduplication role on Windows Server 2016. Per Microsoft, it's using NTFS compression to help save space:

Data deduplication stores more data in less physical space. It achieves greater storage efficiency than was possible by using features such as Single Instance Storage (SIS) or NTFS compression. https://technet.microsoft.com/en-us/library/hh831602(v=ws.11).aspx

1. Should I also enable NTFS compression in the volume's properties (see screenshot below)? Would there be any benefit?

2. What if it was already checked? Should I uncheck it? Would there be any negative effects of having it checked?

I am IT everything man at a small company. I want to design a new infrastructure including a new server and a separate backup server with company wide backup policy.

The most important thing in the company is the SQL Server and its databases. There are 10 database, but only 2 of them are really important. The first one 8GB, mostly text data and numbers. The second one about 300GB with 16GB/month grow containing PDFs and GIFs.

To save the storage current backup policy consists of one full backup per week and 6 differentials. I think its about 350GB per week, 1.4TB per month.

After reading so articles about silent data corruption I decided to try ZFS with Nexenta Community edition.

My question: is ZFS with deduplication good for storing backup files in term of reliability or should i think about some tape backup or something else?

EDIT: I know that right now we cannot predict performance, deduplication ratio etc, but I want to know if it is a good idea at all.

I'm using Nexentastor on a secondary storage server running on an HP ProLiant DL180 G6 with 12 Midline (7200 RPM) SAS drives. The system has an E5620 CPU and 8GB RAM. There is no ZIL or L2ARC device.

Last week, I created a 750GB sparse zvol with dedup and compression enabled to share via iSCSI to a VMWare ESX host. I then created a Windows 2008 file server image and copied ~300GB of user data to the VM. Once happy with the system, I moved the virtual machine to an NFS store on the same pool.

Once up and running with my VMs on the NFS datastore, I decided to remove the original 750GB zvol. Doing so stalled the system. Access to the Nexenta web interface and NMC halted. I was eventually able to get to a raw shell. Most OS operations were fine, but the system was hanging on the zfs destroy -r vol1/filesystem command. Ugly. I found the following two OpenSolaris bugzilla entries and now understand that the machine will be bricked for an unknown period of time. It's been 14 hours, so I need a plan to be able to regain access to the server.

http://bugs.opensolaris.org/bugdatabase/view_bug.do?bug_id=6924390

and

http://bugs.opensolaris.org/bugdatabase/view_bug.do;jsessionid=593704962bcbe0743d82aa339988?bug_id=6924824

In the future, I'll probably take the advice given in one of the buzilla workarounds:

Workaround
    Do not use dedupe, and do not attempt to destroy zvols that had dedupe enabled.

Update: I had to force the system to power off. Upon reboot, the system stalls at Importing zfs filesystems. It's been that way for 2 hours now.

I mean, I can look up the dictionary definition, but why is everyone suddenly talking about it in reference to virtual tape libraries? What's "new" here so that it's so much in the news lately?

NetApp provides block-level deduplication (ASIS). Do you know any filesystem (even FUSE-based) on Linux (or OpenSolaris, *BSD) that provides the same functionnality ?

(I'm not interested in false deduplication like hardlinks).