I have a primary two disk fault tolerant NAS backing up all family devices. My secondary NAS which backs-up the first is out of space. The only reason I have a secondary NAS is to protect data from an issue with the NAS controller of the first unit. I decided that rather than upgrade the secondary NAS from four 18TB drives to 28TB, I would purchase a seven bay NAS. Now, my question is, should I spend the money for a one drive fault tollerance, or is a JBOB configuration sufficient. If I go with JBOB, I can use enterprise drives that I currently own.
Typically you want 75-80% storage efficiency, so 4 or 5 bays in RAID Z/RAID 5 or 8+ bays in RAID Z2/RAID 6. My strategy is to have entirely redundant NAS. If you are expecting to move drives to another NAS in the event of failure, make sure to test that up front. It may require the exact same firmware, drive placement or other limitations.
I'm not a fan of JBOD and other non-RAID storage levels since there is no redundancy and performance is slow. I don't think there are snapshots, deduplication, resilient file systems, and other features. Depending on how they are configured some will fill a drive nearly to capacity before using another. Single drives are even worse when getting full. Why can't you use the drives you have - are they different capacities?
I have a primary NAS, recently upgraded to Five 24TB drives. My secondary NAS had three 18TB drives. I ran out of space, so added a 28TB drive..of which only 18TB is used. I also worked on removing all images from the NAS and saving only one image. This involved culling images from at least 10TB/20 years of storage from an equal number of computers. Some images managed hundreds of copies. My thoughts at the time were to keep adding 28TB drives to replace the 18TB, but within a week I ran out of space. I’m running Synology backup which is designed to backup to another Synology NAS. I currently have 41TB of data on the first NAS. I’m able to use old enterprise drives which amount to four 16TB and three 18TB, which would give me 90TB with one drive fault tolerance & 118TB JBOB. I would need to use the 28TB for my TimeMachine drive. I also backup my MacBook Pro to the NAS and BackBlaze online.
Can you replace one drive at a time from 18->24TB and then expand the array or create a second one?
Some of the post 2022 Synology NAS stink in that they don't like other than the silly priced branded drives.
The last 6 NAS I bought are all QNAP so I can use most any drive. I still have a few older Synology in use that don't care about the particular drives.
EB-1 wrote:
Can you replace one drive at a time from 18->24TB and then expand the array or create a second one?
Some of the post 2022 Synology NAS stink in that they don't like other than the silly priced branded drives.
The last 6 NAS I bought are all QNAP so I can use most any drive. I still have a few older Synology in use that don't care about the particular drives.
EBH
Yes, one drive at a time. This is how I first expanded my primary NAS. I don’t know about drives and Synology in general, but I’ve used 16,18,24 & 28TB Seagate IronWolf without issue. I haven’t tried other brands nor the 32TB IronWolf. The QNAP have some nice features out of the box, like 10Gbe ethernet. I had to install a card to upgrade my primary NAS to 10Gbe. I appreciate your help. You obviously tread in much deeper water than myself.
I like the ZFS of QNAP vs. the btrFS of Synology. At this point I'm not upgrading NAS units, but was planning to continue upgrading drives in the smaller ones <20TB. However, the high costs and lack of availability are problematic. In September 2025 we were getting those Ironed 28TB drives for $480. In January they were $560, but now $690.
EB-1 wrote:
I like the ZFS of QNAP vs. the btrFS of Synology. At this point I'm not upgrading NAS units, but was planning to continue upgrading drives in the smaller ones <20TB. However, the high costs and lack of availability are problematic. In September 2025 we were getting those Ironed 28TB drives for $480. In January they were $560, but now $690.
EBH
Thanks… I’ll take your advice and stay with RAID on the backup NAS. All memory products are out of control expensive. I guess that they should start Leica branding them.
bwcolor wrote:
Thanks… I’ll take your advice and stay with RAID on the backup NAS. All memory products are out of control expensive. I guess that they should start Leica branding them.
I now have a better understanding of the Synology NAS lineup.. at least the lower end that most of us would consider. I picked up an DS1825+ for backing up my NAS and it did not complain when I used 16 & 18TB IronWolf drives, but it would not accept my Samsung M.2 Cache drives. Two Synology 800GB drives were another $1000. I was looking to upgrade my main NAS, which consist of 5 24TB IronWolf drives, so that it could better handle video streaming with active transcoding. The DS1823xs+ would do this, but it will constantly warn me that the 24TB IronWolf drives are not compatible. Reportedly it works, but constantly keeps the Volume in storage warning status. To replace my five 24TB with Synology Enterprise drives is $5000. They do outperform the IronWolf, but this would take more than a passive interest in better video transcoding to make that move..
I believe that the QNAP NAS are mostly higher performing CPU with GPU components, so transcoding would be on the menu. Is there a backup program within the QNAP environment that would allow me to backup their drive to my Synology 1825+? When you transitioned from Synology to QNAP was there an easy migration path, or did you have to copy data one folder at a time? Thanks…
I'm rather surprised that a x25+ doesn't require their branded drives. Is that a new trend for them? The 1825+ looks similar to the now discontinued QNAP TS-873A, both have the V1500B CPU.
In general I start with a fresh array and recopy the data with full verification. It takes a while so is best done in parts, but it is not like I build a new NAS every few months.
There are various file copy tools, but I'm sure you know many of them including some that compare the checksums. The main things I found important are the ability to multi-thread read and writes and to buffer reads. A large buffer helps a lot in the HDD stuttering and performance loss that can occur when the source and target have different performance characteristics.
EB-1 wrote:
I'm rather surprised that a x25+ doesn't require their branded drives. Is that a new trend for them? The 1825+ looks similar to the now discontinued QNAP TS-873A, both have the V1500B CPU.
In general I start with a fresh array and recopy the data with full verification. It takes a while so is best done in parts, but it is not like I build a new NAS every few months.
There are various file copy tools, but I'm sure you know many of them including some that compare the checksums. The main things I found important are the ability to multi-thread read and writes and to buffer reads. A large buffer helps a lot in the HDD stuttering and performance loss that can occur when the source and target have different performance characteristics.
Forgive me for so shamelessly using your experience, but when you speak of buffer, are you referring to M.2 SSD cache? If so, what do you consider large? In the QNAP world are these cache usually setup as read & write? Is QNAP brand sensitive. I know that my Samsung Cache was rejected by my new DS1825+. So, I was able to use the Seagate drives, but not the Samsung M.2 2280 SSD. I’m running out of room on my primary NAS, the DS1522+ and need to consider an expansion unit, which is now discontinued, or moving to an 8 bay NAS..
No, I mean the software, like in FastCopy I set it to 1024MB or more.
I don't use the SSD caching in NAS. I tried years ago and was not able to get anything useful for large files. It seemed to be tuned for IOPs with small files like in a business environment where you have bursts. It's probably better now but I just don't know. I'm sure you can run some test to figure out what value there is and what settings help if any. I would not buy the outrageous branded SSDs. Ironically I have some WD RED NVMes since at one point that was what I could get in the larger capacities.
I tend to work locally and then push large amounts of data back and forth between the computers and NASes. It tends to reach a steady state after a few minutes.
Thanks for all the pointers. I won’t be adding M.2 cache to my NAS that acts as backups. Not many random writes from the primary cache, so no real advantage. You saved me, hopefully from a lot of grief and clarified some basic issues. Also, I’ll not be purchasing Sonology in the future. I think they have one advantage for the home NAS and that is the SHR and SHR2 modes that allow for drives of varying size and yet maximizing utilization. Thank You…
I’ve learned quite a bit about home NAS over the last few weeks. First, Synology is a pain to deal with their hardware limitations, both in terms of old processors and their insistence that we use their storage products. I purchased a Synology DS1825+. It allowed me to populate it with different size drives and it maximizes storage. I used a tolerance for two lost drives (SHR2) with five 24TB and three 18TB drives. Also, the software is pretty bullet proof. It did allow for me to use Seagate IronWolf Pro, but insisted on only Synology Cache M.2, which for two 800GB RAM is pushing $1500. As a note, I did not purchase dual 800GB, but reused my dual 400GB Synology M.2 Cache. There is an optional dual 10Gbe card which can be setup to mimic a single 20Gbe port. I used an 8Bay Ugreen for my main NAS using four 28TB drives in Raid 5. A much faster, more modern unit, but only uses traditional RAID. It comes with dual 10Gbe, which again can mimic a single 20Gbe port. More importantly, it has a much faster processor with GPU and I am able to use the NAS Thunderbolt 4 port to communicate with my MacBook. It took Grok4 and myself a bit of time to make sure that local network did not pass through NordVPN, in other words, so that I could communicate with the Synology and the two NAS could communicate with each other at 10Gbe speed. Lastly, I had to make sure that I communicated with the Ugreen only with the Thunderbolt 4 connection. The final remark is with regards to cost. Storage pricing is no joke. I would have saved many hundreds of dollars if I would have built these NAS even a couple of months earlier.b
