Hello there,
I'm just rambling here, but maybe someone finds this useful: I just decided on what number of hdds to buy. I have crawled the interwebs searching for the definitive answer to the optimal raidz setup and number of disks I thought I'd share my conclusion, and the whys.
My hardware, and experience so far:
I'm your typical home user searching for a good NAS solution. I need rock solid backup of family photos and "important documents", and I'd like to have my media collection available for streaming...
I got lucky and scored some free server hardware from work: HPs with xeon E5606s (4 cores, 2,16 Ghz), ECC memory and a bag full of used 1 TB drives. I set up a 6 wide raidz2. So far FreeNAS has been rock solid, in spite of my failures. I've had disks fail -> resilvered; usb boot drive fail -> reinstall to new usb; update failed (freenas 10 nightlies) -> reinstall; NAS out of commission for 6 months due to "life" -> installed the new version of freenas (11.2). Bottom line: all data is still intact.
So now I'm ready to "invest" in some new storage and consolidate all our datas:
I went back and forth between 4 vs 6 hdd setup, and whether to go for 4 TB or 8 TB hdd
(My) Conclusion: 4 hdd, raidz2, of 8 TB hdds.
- Yes that's 50% "loss of space", but I have grown to accept the price of redundancy.
- 4 TB and 8 TB have almost the same price/TB (today)
- 4x8TB is only slightly more expensive than 6x4TB. I consider 8 TB hdd more "future proof", and available TB is the same for both (~16).
4 disks are 2/3 the cost of 6, that's a lot. 33% (on top of today's black friday deal).
With a 4 hdd setup I can double the available capacity with 2 extra hdds, if needed.
"But you cant add hdd to vdevs?"
True, not today, but openzfs is working on it. AND; I will most likely discover the need to expand to a 6 disk z2 before it's a problem to offload my data to some other device temporarily.
Also, I only have 6 sata ports on my motherboard (unless I buy some pci-sata hba). A 4 disk vdev leaves one for a boot ssd (better than using usb). And I have an unused SSD from an old system.
That spare SATA port? Perfect for a backup hdd. Raidz is redundant, not backup, this way I can have internal backup, in addition to the copies stored on my devices. This is only for "important stuff", so I do not need lots of capacity, can probably use one of the old drives. Spare sata can also be used in case of drive failure, upgrading hdds etc. just so many options.
Last: According to backblaze stats I should expect ~1% failure rate. With 4 drives I'm actually less likely to experience a drive failure.
cheers :)
I'm just rambling here, but maybe someone finds this useful: I just decided on what number of hdds to buy. I have crawled the interwebs searching for the definitive answer to the optimal raidz setup and number of disks I thought I'd share my conclusion, and the whys.
My hardware, and experience so far:
I'm your typical home user searching for a good NAS solution. I need rock solid backup of family photos and "important documents", and I'd like to have my media collection available for streaming...
I got lucky and scored some free server hardware from work: HPs with xeon E5606s (4 cores, 2,16 Ghz), ECC memory and a bag full of used 1 TB drives. I set up a 6 wide raidz2. So far FreeNAS has been rock solid, in spite of my failures. I've had disks fail -> resilvered; usb boot drive fail -> reinstall to new usb; update failed (freenas 10 nightlies) -> reinstall; NAS out of commission for 6 months due to "life" -> installed the new version of freenas (11.2). Bottom line: all data is still intact.
So now I'm ready to "invest" in some new storage and consolidate all our datas:
I went back and forth between 4 vs 6 hdd setup, and whether to go for 4 TB or 8 TB hdd
(My) Conclusion: 4 hdd, raidz2, of 8 TB hdds.
- Yes that's 50% "loss of space", but I have grown to accept the price of redundancy.
- 4 TB and 8 TB have almost the same price/TB (today)
- 4x8TB is only slightly more expensive than 6x4TB. I consider 8 TB hdd more "future proof", and available TB is the same for both (~16).
4 disks are 2/3 the cost of 6, that's a lot. 33% (on top of today's black friday deal).
With a 4 hdd setup I can double the available capacity with 2 extra hdds, if needed.
"But you cant add hdd to vdevs?"
True, not today, but openzfs is working on it. AND; I will most likely discover the need to expand to a 6 disk z2 before it's a problem to offload my data to some other device temporarily.
Also, I only have 6 sata ports on my motherboard (unless I buy some pci-sata hba). A 4 disk vdev leaves one for a boot ssd (better than using usb). And I have an unused SSD from an old system.
That spare SATA port? Perfect for a backup hdd. Raidz is redundant, not backup, this way I can have internal backup, in addition to the copies stored on my devices. This is only for "important stuff", so I do not need lots of capacity, can probably use one of the old drives. Spare sata can also be used in case of drive failure, upgrading hdds etc. just so many options.
Last: According to backblaze stats I should expect ~1% failure rate. With 4 drives I'm actually less likely to experience a drive failure.
cheers :)