I have an EX4100 that’s about six years old. I populated it with four 4TB HDD from other desktop PCs I had. As these HDD are older than the NAS I think it might be a good idea to replace them. I’ve had to hard reboot the NAS a couple times in the past four month. The dashboard says I have around 9.3TB free in RAID 5 configuration.
If I read other articles correctly, I can hot swap the drives, and if the Expand Capacity option is available on the dashboard, increase the drives to 6TB each. Is this correct?
That should work.
However. . .if the drives are questionable. . . I might look for a way that doesn’t involve 4 raid rebuilds to happen.
9.3TB free in a 4TBX4 raid 5 I believe translates to 12TB capacity - - - → so you have under 3TB in storage. I would STRONGLY recommend
- copy ALL the data to an external drive as a backup.
- Replace all four drives in one shot.
- Copy data back from backup.
When removing the 4 old drives; they are slot dependent. Don’t mix them up if you ever need to use them again. Make sure you label which drive comes out of which slot.
(DO NOT USE SMR DRIVES. DO NOT USE WD RED DRIVES. Use either Red Plus, Red Pro, or another brand for which you are sure to get CMR drives)
Thanks for the tip on cmr vs smr drives. I went to another web site and it basically said the same thing. So why does WD claim the basic Red drvie can be used in an NAS? Money?
Short answer: money.
Went a long way towards reducing wd credibility in the market, and forced them to create the “plus” line.
Do not buy any hdd from any vendor for any purpose without verification its cmr.
Great. I used the instructions from another thread. I pulled one 4TD drive and inserted a new 6TB drive. Instead of getting the rebuild RAID 5, the EX4100 wanted to start from scratch. Plus, Drive 3 is now reporting as failed.
Wha’ hoppened?
By the way… I couldn’t find any place where I could backup 4TB of data. I tried dropbox, but it wouldn’t accept several file types, such as .TXT. Should I put the extract drive back in?
I think you may have missed step 1.
At this point, you have a high probability of losing 100% of the data.
Your first step needs to be obtaining an external drive. It doesn’t matter what drive you get; as long as it has the capacity*
Second step will be to copy the data from the NAS to the external drive. Don’t get fancy; just windows drag and drop works fine. Do it in reasonable chunks (200-300gb) (not one massive 4tb copy). Don’t use PC over Wifi - - use a wired network connection. If you have a laptop without a network jack; you will want a USB jack.
Now, WD NAS units commonly misreport drive health. You want to take a look at the S.M.A.R.T. data to see if the drive is actually bad. @cerebus has built some WD NAS tools for this purpose - - > suggest you look him up.
What would I do?
- GET A DRIVE.
- Reinsert old 4TB drive; Reboot NAS. hope you only get one red light.
- Copy all data from NAS to external drive.
- With data secure, replace 4TB drive with new 8tb drive.
*if possible, get an external HDD that has a CMR drive inside. Dig in the specs to confirm. Note that the 2.5" HDD’s are all SMR in 2023 (I don’t buy them anymore). You don’t need anything fancy. You don’t need any features other than a standard USB 3.0 connection. But honestly . . . anything will do. Just do something.
I put the old drive back in and rebooted. Everything was copacetic. Going to EX4100 dashboard, all four drives are listed as good.
I did try using dropbox and it froze after only 27% and has been frozen for 20 hours. I guess it’s Hello WD Passport.
Indeed. Yes; backup your data. 
Makes a NAS “red light” a much less scary experience.
I did a bit of research.
Bottom line - - - I would avoid the MyPassport drives and any of the “mybook” desktop drives smaller than 8TB. They are likely SMR drives. . . which are undesirable.
In snooping. . .I found this disheartening page which basically says “we put any drive we want in a drive enclosure”. The page was updated last week.
Digging further, looking at the WD drive specs in general, it appears that larger drives (over 8TB) are all CMR technology. This means if you want a CMR drive; you need to either buy a known drive and stick it in an enclosure, or just buy a larger device.
Further. . . figure any 2.5" drive (i.e. all the “MyPassport” drives) are SMR and are (unfortunately) to be avoided. (I used to swear by this little drives. . .but no more. Now I just spend (alot) more on SSD portable drives)
BTW: The same basic story is true for Seagate; although for Seagate I would make the cutoff 10TB.
