The Mini Plus' feature set is that of FreeNAS 8.3.1. I'll be diving into detail on many of its features shortly. But here is a feature overview taken from its data sheet:
- 4 bay enclosure - 4 SATA drives
- Max capacity 12 TB
- Software, ZFS-based RAID
- RAID-Z, RAID-Z2, ZFS Mirror, ZFS Stripe
- 10/100/1000 Ethernet port (can add 2nd Ethernet port)
- File sharing protocols supported = AFP, CIFS, FTP, NFS, SSH, SFTP, TFTP
- iSCSI supported with multiple IP address capability
- User authentication via Active Directory and LDAP
- UFS2 Volumes, including gmirror, gstripe, graid3
- ZFS Volumes with quotas, snapshots, compression, replication, datasets
- Reversible upgrade process
- Automatic status email notifications
- Easy to use web GUI
- Configurable replication, snapshot, scrubs, cron job management
- Multiple language and keyboard settings
- Supports VLANs and multiple Ethernet interfaces
- SMART monitoring
- UPS management
- USB 3.0
- Windows ACL and UNIX file system options
- ZFS snapshots visible in Windows
- BSD-licensed tmux utility
- dmidecode harware diagnostic utility
iXSystems' quick start guide instructs new customers to connect a monitor and USB keyboard to the Mini on first boot so you can determine its IP address. But you don't really need to do this. If you connect power and Ethernet and examine your router's DHCP table, you'll find a device called "freenas" and its IP address. You can also use Fing to find the IP addresses of every device on your network.
The FreeNAS Mini Plus can be configured via the command line or a web GUI. I found the web GUI fairly intuitive, with menu options displayed in a pane on the left, as well as tabs on the right, shown below. However, IE10 does not seem to work with fully with the FreeNAS GUI as it doesn't display the menu options on the left. Chrome and Firefox seemed to work fine. Command line access is available in a window from within the GUI or via SSH.
Notice in the menu screen on the bottom a few lines of text output. This is a nice real-time display of the device log messages as they occur. Clicking on this output brings up a scrollable window of log messages.
The web GUI has six main menus, accessible via icons across the top of the page or via a menu pane on the left. Each of these menus has numerous tabs and subtabs displaying configuration options. The Table 2 shows the majority of the configuration options for FreeNAS. Note, the Services menu has 16 submenus, so I displayed it in two rows in the below chart.
|System||Cron Jobs||NTP||Reporting||Rsync Tasks||SMART Tests||Settings||Sysctls||Sys Info||Tunables|
|Network||Global||Interfaces||Link Aggregation||Summary||Static Routes||VLANS|
|Storage||Snapshot Tasks||Replication Tasks||Volumes||ZFS Scrubs|
|Sharing||Apple (AFP)||Unix (NFS)||Windows (CIFS)|
|Services.1||Control||Active Directory||AFP||CIFS||Dynamic DNS||FTP||iSCSI||LDAP|
Table 2: Menu tree summary
In addition to the six main menus, FreeNAS provides the ability to display system processes in a command line output, equivalent to the Linux command top, shown below. You can also bring up a shell window to configure or interact with the device via the command line. There are also useful buttons to logout, reboot and shut down the device, as well as a button to bring up links to online help documentation, and finally a button to view current system alerts.
iXsystems provides a ten page startup guide for the FreeNAS Mini and Mini Plus with some basic instructions on how to get up and running. The remaining FreeNAS documentation is available on line and via a link on the FreeNAS GUI help button. I was pleasantly surprised by the FreeNAS 8.3.1 Users Guide. It is clearly written, well organized and includes useful configuration examples.
A strength of the FreeNAS system is ZFS (Zettabyte File System). [A Zettabyte is 10^21 bytes.] The FreeNAS Mini and Mini Plus run ZFSv28. ZFS is a form of RAID that strives to eliminate issues with data integrity that can go undetected via disk, software and other hardware error detection tools. The FreeNAS Mini's ZFS RAID options include ZFS Striping, ZFS Mirroring, RAIDZ1 and RAID Z2. These four RAID options are similar to RAID 0, 1, 5 and 6, but with ZFS' greater data integrity capabilities.
Specifically, ZFS overcomes a known RAID weakness known as the "write hole." When data is written to a RAID5 or higher array, both the data and the parity data are written to the volume, sequentially. If a an unexpected shutdown or power outage occurs between the writing of a data block and the associated parity data block, that portion of data will be inconsistent. In the event of a disk failure, RAID5 will not be able to recover that portion of data.
ZFS also writes parity data, but writes the parity data simultaneous to writing the actual data, maintaining disk consistency. This allows ZFS volumes to avoid the write hole. ZFS can also fix corrupt data by comparing each data block against a checksum as it reads the data. If the checksum doesn't match, ZFS finds the corrupted block, reads the parity, and reconstructs the data.
The ZFS file system is a software-based RAID system. Subsequently, if a hardware RAID controller is present, FreeNAS recommends it is placed in JBOD mode so the FreeNAS software can control the array. Further, to achieve high degrees of data integrity, ZFS is memory intensive. FreeNAS recommends 1 GB RAM for every 1 TB of storage. This is why the Mini Plus has an unusually high amount of memory for a NAS—16 GB.
A limitation to ZFS software RAID is that disk drives are "hot pluggable", but not "hot swappable". Hot-pluggable means you can add a new drive to a running system if there is an open bay. You can also remove a drive while the NAS is running, but you have to reboot before you add a new drive back in. Hot-swappable means drives can be removed and added without rebooting or power cycling.
The FreeNAS Mini Plus' motherboard has four SATA ports, two support SATA 6.0 and the other two support SATA 3.0. Thus, in a four drive array, you're only going to get the benefit of SATA 3.0Gb/s. The FreeNAS Mini Plus' motherboard supports RAID 0, 1, 5, and 10 using Intel Rapid Storage, which is disabled, allowing the FreeNAS operating system to control the disks array via ZFS.
The ZFS file system includes another data integrity feature called Scrubs. This feature examines the entire storage system on a scheduled basis, reads every data block, and repairs them as needed. A regularly scheduled scrub is enabled automatically upon creating a volume