Hi all, long time listener first time caller,
I have a WD PR4100, old equipment but it suits my needs, I maxed out the ram when I first bought it 5 years ago and it has 4 drive bays. Right now I have four 4TB WD Red Pro/Premium drives inside in a RAID1 setup. One of the drives is more recent and the other 3 are from when I bought the PR4100 5 years ago.
It is time for me to replace the drives, one started failing awhile back and that is why it was replaced, but in anticipation of the other 3 failing eventually I would like to upgrade them all and to take this opportunity to replace them with higher capacity drives.
First question, is there an upper limit for capacity on the PR4100 and can I just drop new 20tb+ drives in there and expect them to work?
Second question, do I replace them one at a time and in doing so would the system rebuild the RAID 1 setup or is there a better way?
This is for local backups and a self-hosted media library, not commercial or professional use.
I am not looking to build a new NAS system right now as the PR4100 is working as intended without much hassle but in a year or so I may need a more complex and professional NAS/server depending on if I get back into video production more fully.
Thank you for your time and for everyone posting and providing help in this community.
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upper capacity
There may be an upper limit, but on Amazon there is a 72 TB version that would have to come with at least 18 TB drives. If 18 TB is fine, 20 TB is also probably fine, but I couldn’t find any reports by people saying they’d loaded 20 TB drives into theirs without issue.
procedure
You could also clone them yourself, but you’d want to put the NAS into read only mode or take it offline first.
I think cloning drives is generally faster than rebuilding them in RAID, as well as easier on the drives, but my personal experience with RAID is very limited.
Basically, what I’d do is:
- Take the NAS offline or make it read-only.
- Pull drive 0 from the array
- Clone it
- Replace drive 0 with your clone
- Pull drive 2 (from the other mirrored pair) from the array
- Clone it
- Replace drive 2 with your clone
- Clone drive 0 again, then replace drive 1 with your clone
- Clone drive 2 again, then replace drive 3 with your clone
- Put the NAS back online or make it read-write again.
In terms of timing… I have a Sabrent offline cloning hub (about $50 on Amazon), and it copies data at 60 Mbps, meaning it’d take about 9 hours per clone. Startech makes a similar device ($96 on Amazon, that allegedly clones data at 466 Mbps (28 GB per minute), meaning each clone would take 2.5 hours… but people report it being just as slow as the Sabrent.
Also, if you bought two offline cloning devices, you could do steps 1-3 and 4-6 simultaneously, and do the same again with steps 7-8.
I’m not sure how long it would take RAID to rebuild a pulled drive, but my understanding is that it’s going to be fastest with RAID 1. And if you don’t want to make the NAS read-only while you clone the drives, it’s probably your only option, anyway.
Thank you for your thorough response!
I figured there wouldn’t be an upper limit but I’ve been burned before in the past with trying to use too big of a drive in various applications over the past 3 decades of computer use so I wanted to be sure before dropping a lot of money on new high capacity drives for the NAS.
When I replaced the one drive a few months ago I just removed the faulty drive from the NAS and slotted in the new drive in its place and the NAS copied everything and was up in running again in a few days. It was only 4TB but it took awhile. I know it should be able to if I replace like for like sized drives but I wasn’t sure how it would be have if I start replacing 4TB drives with 20tb drives.
I do have a drive cloner already, buried in an old tech box in the garage that I could use but it is several years old (6 maybe?) so I am sure it isn’t as fast a a newer one. Maybe I will pick up one or two of the ones you suggested to speed the process along.
I don’t know that a newer drive cloner will necessarily be faster. Personally, if I’d successfully used the one I already have and wasn’t concerned about it having been damaged (mainly due to heat or moisture) then I would use it instead. If it might be damaged or had given me issues, I’d get a new one.
After replacing all of the drives there is something you’ll need to do to tell it to use their full capacity. From reading an answer to this post, it looks like what you’ll need to do is to select “Change RAID Mode,” then keep RAID 1 selected, keep the same disks, and then on the next screen move the slider to use the drives’ full capacities.
Ah ha! Thank you, this was one of my worries with increasing the capacity, I was worried that even after replacing the 4TB drives with larger capacity drives that the new drives would still only be limited to the lower capacity partitions. I wasn’t sure if there was a way to increase them.
My work around for this was to back up all the data on the NAS currently (only ~7.2TB) onto an external drive. Put the new larger capacity drives into the NAS, format them properly and setup the RAID as needed and then transfer the data back onto the new fresh larger capacity drives in the NAS from the external drive.
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Looks like that NAS was originally sold with up to 40tb capacity so it shouldn’t have any issues with larger drives. Seems like the “my cloud os” is based on Linux so unless WD built in some weird limit, it should work with 20tb drives.
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I don’t have an answer here, never had to rebuild an array. You might be able to use clonezilla which can do a block by block copy of disks and then expand the volume in the OS if it supports it. This is just conjecture, I’ve never done it with a raid array.
- Cool, thank you for you input on using larger drives. I figured it could but wanted to be sure before spending the money.
- I know the PR4100 will rebuild itself if you remove a faulty drive and replace it with a new one, I am just not sure how it would work when upgrading the size and if there would be a better way to go about doing so than just letting the PR4100 do the work itself.
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