SSD vs HDD

[tjrose91]

what is better for long term storage for an extra copy of my data, already have a true nas with a pool of 4x10tb in ZFS2 i think so only 20tb of usable hard drive space i wanted to make a new pool of either

 

4x4tb sata SSD or NVME,  or 4x5tbHDD

 

the nas im using is always turned on

[Shimejii]

If its powered on, doesnt really matter they are both the same roughly. If powered off for long periods? HDD. 

[emosun]

well the hard drives will be cheaper and store long term data the same as an ssd.

[tjrose91]

14 minutes ago, emosun said:

well the hard drives will be cheaper and store long term data the same as an ssd.

yep the 5tb 2.5in HDD are about $150 and an SAMSUNG 870 EVO 4TB 2.5  is about $225, i was planing next year to create two more pools,

an extra sata pool and an NVME pool granted i dont use the nas that much but i was planing to go Samsung 870 Evo for the Dram cache and Teamgroup 4tb NVME gen 3 as the product i got before also has a dram cache and is about the same price as the 5tb HDD

 

 

[Agall]

Outside of redundant HDDs, magnetic tapes, but then you'd have to get a reader/writer and tapes, so redundant HDDs are the best option for most people. That's even if you're looking to store them offline in a chassis some where, otherwise, magnetic tapes  

 

SSDs I wouldn't trust without a lot of redundancy, though they're supposed to retain data for as long as 10 years. I just wouldn't trust them as much as an HDD or magnetic tape to store data long term.

[LIGISTX]

1 hour ago, tjrose91 said:

what is better for long term storage for an extra copy of my data, already have a true nas with a pool of 4x10tb in ZFS2 i think so only 20tb of usable hard drive space i wanted to make a new pool of either

 

4x4tb sata SSD or NVME,  or 4x5tbHDD

 

the nas im using is always turned on

I’d argue a second copy of your data on the same machine or in the same physical location is not worth doing. The chance of losing data on an array that has 2 parity drives for only 2 data drives is EXTREMELY low. The only conceivable way this would happen is an electrical issue that affects the entire machine, or potentially your entire house…. Or a natural disaster. 
 

You need to copy your data either to the cloud, or a physically separate (and distant) location. Having a copy physically next to your current copy is not worth doing imo. 

[Blue4130]

5 hours ago, tjrose91 said:

yep the 5tb 2.5in HDD are about $150 and an SAMSUNG 870 EVO 4TB 2.5  is about $225, i was planing next year to create two more pools,

an extra sata pool and an NVME pool granted i dont use the nas that much but i was planing to go Samsung 870 Evo for the Dram cache and Teamgroup 4tb NVME gen 3 as the product i got before also has a dram cache and is about the same price as the 5tb HDD

 

 

Is there a reason why they have to be 2.5 inch drives? 3.5 would be drastically cheaper and tend to be more reliable (unless you get enterprise 2.5 drives)

 

I would also not keep the backup on the same machine that it is backing up. Highly insecure.

[Electronics Wizardy]

Those 5TB 2.5in drives are SMR and gonna be very slow in some workloads. I'd go all SSD here.

 

SSDs should be more reliable, esp since all the 2.5in drives aren't great it seems.

[Bersella AI]

Agree with LIGISTX. Since you have had a RAID Z2 array that is considered robust enough for data integrity, it's unnecessary to add extra drives to the same machine for additional parity. An off-site storage would be a cleverer choice here, for example, a single 20TB hard drive with a portable enclosure, to back up all of data monthly or bimonthly, and be placed elsewhere.