I started out with a diskless EX4 and added disks one-by-one (trying to simulate the general use case where people buy drives only when they want to expand capacity):
With one disk, I could initialize a JBOD volume. After adding a second disk - I could change to RAID-1 without loss of existing data. I added a third disk - migrated to RAID-5 without data loss. Now, after adding the 4th disk – I found that
I was given an option to change to RAID-5 (I was already in RAID-5 with 3 disks) – but this required all disks to be formatted again. I couldn’t find a way to expand from 3 disks to 4 while remaining in RAID-5 and keeping existing data intact.
Is this feature (online RAID capacity expansion) available in the firmware? If so, where do I find that option in the UI? If not, I find it really strange that there are a number of advanced features (for example, Thecus doesn’t allow single disk JBOD to RAID-1 migration in their NAS units, but WD allows that in the EX4), but this seemingly straightforward (and often taken for granted) feature is missing.
Other minor complaints I have are:
Fan speed seems to top out at 1035 rpm. During RAID-1 to RAID-5 migration with WD RE drives, I found HDD temperatures reaching 58 - 60 C. Any reasons not to go in for a better fan, given that we have variable fan speed control? (I have to say the fan is pretty quiet)
There is no option to view detailed logs. For example, I want to know when disk rebuild starts (I see that the Notification list gives some basic info like when a new disk gets inserted or when volume rebuilding completes, but information like when volume resizing started and finished is not available). I also checked under /var/log , but couldn’t find the necessary information in any of the files.
The NAS seems to be running some sort of scraper in the background which might affect NAS performance (I see it does take up a lot of CPU cycles). I have to see the difference in performance with the media server enabled and disabled to see how bad the effect is.