The EX4 supports most all the features of the single-bay My Cloud, which Craig covered pretty well in his review. So I'm just providing our customary feature bullet-lists below.
Features common to My Cloud / My Cloud EX4:
- SMB/CIFS network filesystems
- AFP ( for Apple Time Machine)
- NFS (only to default Public mount)
- FTP server
- Apple Time Machine target
- UPnP Certified AV/DLNA 1.5 Media Server (Twonky 7)
- iTunes Server
- SmartWare for Windows bundled client backup application, unlimited licenses (local network). 3 licenses for SmartWare Pro also included
- User level permissions (no groups, no quotas)
- HTTP web administration (no HTTPS)
- Email alerts (w/ built-in SMTP service for no-hassle setup)
- Remote access to shares via WDMycloud service
- WD Photos photo viewer app for iOS, and Android (requires WDmycloud service)
- My Cloud Mobile App for iOS, Android and Windows Phone
EX4 additional features:
- Single drive, Span, JBOD, RAID 0, 1, 5, 10 volumes.
- RAID auto-rebuild enable/disable
- RAID level expansion: JBOD to RAID 1 & 5; RAID 1 to 5
- Multiple volume support.
- Volume level encryption
- User groups and storage quotas
- WebDav support
- FTP server with max user, bandwidth, SSL/TLS and IP blocking
- DFS support
- Active Directory support
- ISO mounts
- Dual Ethernet LAN ports with jumbo frame, IPv6, link aggregation and failover
- USB and Network UPS support
- Real-time resource monitoring (CPU, Memory, Network, Processes)
- Disk and system diagnostics
- Email and SMS notifications (built-in SNMP service)
- Backup to/from USB drive
- Network backup (only to other My Clouds)
- Internal drive-to-drive backup
- Cloud backup to Amazon S3 and ElephantDrive
- iSCSI targets
- iSCSI initiator
- HTTP, FTP, BitTorrent downloaders
- Web File viewer (Web browser) with upload / download
- Add-in Apps (aMule, IceCast, Joomla, phpBB, phpMyAdmin, SqueezeCenter, WordPress, Git, NZBGet, Transmission
- NFS, SMB2, LLTD, SNMP, SSH protocols
- Dynamic DNS (DynDNS.org, no-ip.DDNS, tzo.com)
- Whole-volume "snapshot" backups (supported on My Cloud)
- RAID expansion
and level migration RAID auto-rebuild enable/disable
- Print server
The admin GUI adopts the same new style as the single-drive My Cloud, but with a few tweaks. Resource Monitor and App count replace the Shares and Content Scan widgets on the uni-drive My Cloud.
My Cloud EX4 home page
As the feature list shows, there are a lot of additional functions built into the EX4, including iSCSI target and initiatior. So it's possible to build yourself a little SAN using multiple EX4s.
There is no simple / auto RAID mode like NETGEAR, Synology and other competitors have. But you do have a few RAID level migration options and WD says they plan to add RAID expansion in a future firmware release as well as logging support.
Backup features have been significantly expanded over the single-drive My Cloud's whole-volume "Snapshot" feature, with options for backup to/from USB, over the network to only other My Clouds, internally and cloud. The USB and network backups can't be scheduled, but the internal backups can. For cloud backup, both Amazon S3 and ElephantDrive are supported.
My Cloud EX4 home page
If you're handy with creating rsync.conf files via SSH, you can also run network backups to standard rsync targets. For client backup, WD throws in 10 licenses of its Smartware Pro Windows client. For MacOS, you're expected to use the EX4's Time Machine support.
The gallery below has screenshots and commentary for some of the added features.
Since this is our first time with the EX4, I decided to perform a drive pull test. With the system operating normally and with email alerts set up, I popped Drive 4 out. The front panel display immediately showed System Busy Please Wait and the power light started flashing. About one minute later, the display changed to Volume 1 degraded and I received an email telling me the same thing.
I then re-inserted the drive, waited a bit, but saw nothing happen. So I logged into the EX4 and found a trouble indication on the Home page. I then navigated to the Storage > RAID page and found Auto-rebuild is not enabled by default, so I manually started a rebuild. The initial RAID 5 build completed in around 10 minutes, but the rebuild showed an estimated 630 mins rebuild time. The intial build must skip bad block checking / mapping, while the rebuild does not. Through all of this I had normal access to the degraded RAID 5 volume.
This review was delayed a few weeks while WD and I tried to figure out why running the NASPT Directory Copy Read test quickly gobbled up all of the RAM in my testbed machine.
The short story is that WD finally traced the problem to oplocks being enabled by default on all volumes. Oplocks can help improve performance, but they also can cause problems in real-world use if used inappropriately. WD hadn't run into a problem with other reviewers, but thought it would be best to give users the option of controlling oplocks directly in a future firmware update.
WD also gave me a workaround so that I could complete testing, which I'll pass along to you. You just need to enable SSH access, log in and edit the /etc/samba/smb.conf file, changing Oplock=yes to Oplock=no for the desired share(s). Note that the change does not survive a NAS reboot or shutdown.
The EX4 was tested with 1.02.08 firmware using our standard NAS test process and with oplocks disabled on the test volume. Results are shown below in the Benchmark Summary below.
RAID 5 File Copy write works the Marvell processor the hardest, dropping throughput to around 34 MB/s. The same test using NASPT fares better, with throughput back up around 54 MB/s. RAID 5 read for the Windows and NASPT file copy methods produced the inverse result, with NASPT read around 47 MB/s and Windows up at 68 MB/s.