I hope that I’m not only helping myself by these questions but also helping others who didn’t find answers to such questions…
Before we start, let’s agree on few points. I read a lot about all raid options Raid-0, Raid-1 , Raid-0+1, Raid-10(1+0), Raid-5, Raid-6, Raid-50, Raid-51, Raid-60, and Raid-61. So the questions here are not about principles of these RAIDs work, I think there are a lot of reference for all of them.
My questions are specific to WD PR4100 and how does it apply the previously mentioned principles (practically):
1- In the 40TB pre-configured, what are the drives installed? RED or RED-PRO? cash? RPM? transfer rate?
2- In RAID-10, what is the drive bay arrangement? (1=2 + 3=4) or (1=3 + 2=4) or (1+2 = 3+4)
In other words:
[Option 1]: If I lost disk 1 I can rebuild from disk 2 (and vise versa), and if I lost disk 3 I can rebuild from disk 4 (and vise versa)
[Option 2]: If I lost disk 1 I can rebuild from disk 3 (and vise versa), and if I lost disk 2 I can rebuild from disk 4 (and vise versa)
[Option 3]: If I lost bay 1 and 2 (both), will I be able to rebuild my data from 3+4?
(This can help the use of 2 different types of HDD (EX. WD-Ultrastar & WD-Red) and try avoiding having a similar life span which can can affect the recovery process when all HDDs age together)
3- In RAID-10, does the read happen from one of the sides only? (one raid-0 side)
(If that is the case, Using WD purple can help saving on cost and add more durability/heavy duty for a continuous writing on the side which is writing and not usually used for reading)
4- Can I setup 3 drives to be working on raid-0 or raid-5, and keep one as a JBOD and make a scheduled daily backup of my critical data (folder/share) from the Raid-0 to the JBOD?
5- RAID-5 redundancy is a great balance between space & data safety and it makes sense why you set it as default but I’m concerned about the compression speed for the parity section and how far does it affect the write speed on the PR4100 (will the user still feel the speed difference even with the Pentium quad-core CPU and after an upgraded RAM to 16GB on the PR4100?)
In other words, Is there any comparison chart/benchmark for read & write speeds for JBOD (Control), Raid-5, Raid-10, and Raid-0 on PR4100 specific? (want to know how much speed is sacrificed for the extra storage to help decide between RAID-5 & RAID-10 or even Raid-0 with External backup)
6- I have multiple “my passport 4TB” USB drives, and I read that PR4100 can backup to USB drives but I have 2 questions.
A- How will it interact with password protected “My passport” (will it ask for password? can I save the password so It will automatically unlock for the scheduled backups in the future?)
B- As I have mentioned, I have multiple WD MY passport, will the PR4100 be able to differentiate between them for different backup activities for each? (Ex. 1 drive is to backup My document while the other is to backup family photos, a 3rd one for Media, and a 4th for work projects)?
7- Last question, on Youtube, one review said that PR4100 did not detect a faulty drive and kept running in Raid-1 mode without warning the used about the bad drive. This is very critical because if a user didn’t know that he/she lost one drive, the situation will be disastrous when the second fails and all the data get lost with no way to recover. Was this issue resolved? what types of warning does PR4100 generates (buzzing/beeping/LED/software pop-up)?
I know that my questions are so specific and geeky a bit but I want to make a knowledgeable decision and help others do the same so they know what to expect for their money.
I’m not expecting answers for all the questions from one person, but you can share your experience or knowledge about any of the points above.
Thank you all in advance for your kind support.