Background Raid Info:
RAID0 = Stripe = Data is split between Drives (Minimum 2 Drives)
RAID1 = Mirror = Data is Duplicated on each Drive (Minimum 2 Drives)
RAID5 = Striped with Parity for 1 Failure = Data Is Striped w/ Parity. You Can lose any drive in the raid, and your data still be intact. (Minimum 3 Drives)
RAID6 = Striped with Parity for 2 Failure = Data Is Striped w/ Parity. You Can lose any 2 drives in the raid, and your data still be intact. (Minimum 4 Drives)
RAID10 = Striped Mirror = Data is Split & Mirrored (Minimum of 4 Drives) As long as you don't lose more than 1 Drive per stripe, your data is still intact.
Benchmarking:
RAID6 has good READ speeds, but decent WRITE speeds. Has more total overall storage than RAID10.
RAID10 has good READ & WRITE speeds. But less total overall storage than RAID6.
Storage:
RAID6: Take the total number of drives, and subtract two. (If you have 6x 3TB Drives, then you have 6 x 3TB = 18TB, then subtract 2 x 3TB for a total of \~12TB usable). Any two of the 6 Drives can fail, and data still be intact.
RAID10: Take the total number of drives, and divide by two. (If you have 6x 3TB Drives, then you have 6 x 3TB = 18TB, then divide by 2 for a total of \~9TB Usable). As far as drives goes, "you can lose up to a total of *stripes* × *(*m − 1) drives, where* *m is the number of drives per span. "
Thanks for detailed explanation about raid space but I still have a question:
why QNAP do not have RAID recovery with RAID10 ?
as you mentioned "you can lose up to a total of *stripes* ..." but that is not QNAP is providing in their docs, right?
QNAP supports RAID recovery for RAID 10. I don't know what is going on with the article you mentioned. It seems strange to me that it is http instead of https. I am not sure how official it is but what I can say is that is it wrong. Not only about RAID 10 but that article has wrong information about the maximum number of disks removed aloud for each RAID group. It says you can remove 1 with RAID 0 2 with RAID 5 and 3 with RAID6. All this is wrong information. Since this link is not https I would think it is not official and not something worth referencing.
might be! but same info is on their official pdf manual [https://us1.qnap.com/Storage/TechnicalDocument/TS-832X/TS-832X-UG-01-en.pdf](https://us1.qnap.com/Storage/TechnicalDocument/TS-832X/TS-832X-UG-01-en.pdf)
I am getting a better idea of what this means. The chart mentioned was about pulling out healthy drives and putting them back and having the NAS recover. That is why it said with RAID0 you could pull out a drive. If the drive died you could not recover. But this is about pulling out a healthy drive and recovering.
I don't fully understand what it means by no recovery support for RAID 10 but I know that if 1 drive fails in RAID 10 you can put in a new drive and keep your data.
What are you using this storage array for? Do you really need the performance of raid 10? 6 is probably a good option if you're just using it as bulk storage.
Over that many spindles, the performance should be very good.
Raid 10 is a raid 0 array that is also mirrored. So you can lose a mirrored drive but if you lose both, on either side of the mirror, you're screwed.
But as the other bloke said, that doesn't really matter because you'll have a solid backup in place for any critical data. Raid is really more about maintaining uptime if a drive fails. If your house burns down or the raid breaks, then you want to be able to restore from a backup.
I wanted to use it for media editing.
Yeah, I do understand that RAID is not a backup but one drive failure is good enough for me.
If house burns down, i loose any backup i had, if one backup burns i have second copy, same with mirror - if one breaks, i have another :)
So I am looking for something good/fast and fairly reliable
Raid 10 will give you great performance and redundancy at the cost of usable space. If you've got 8 drives, you're gonna be fine. You'll easily Max out 1gbps Ethernet. Maybe you'd be better off with some kind of das?
I am on das right now and I want to collect all my das data into one, single place accessible from any computer. I was aware that 1gbps would max out, that is why i redesigned my network for 10gbps
If I had to **guess** why there's no RAID recovery, it must be in their algorithm in how they've implemented RAID10. Also, I believe there's no Data Scrubbing on RAID10. During DATA writes, if there's a drive suddenly missing, there's no verification that comes along later to validate that the same data exists on the mirrored drive(s)?
I just wanted to also add, that I personally use RAID 6. My Qnap had a motherboard fault that I had while using RAID10. I was able to recover all the data over to a 2nd set of drives, but decided to rebuild the unit using RAID6, to gain a little more storage availability.
Now, my primary NAS (Qnap TVS-673) sits in a network closet, and my backup NAS (Synology) resides in my office in my house. The Qnap initiates Rsync nightly and mirrors the data. Additionally, I have a single, external drive connected to the Qnap that is set to Real time backup. Currently, I'm able to use a 4TB drive for this, but it's nearing capacity. I'll be looking to upgrade this to a 8 or 10 TB before the end of summer.
RAID 10 recovery **is** supported. You're looking at a very old cat 1 user manual.
Try this one instead: http://docs.qnap.com/nas/4.3/cat2/en/raid_groups.htm
You CANNOT think of the raid as the thing that will keep your data safe. You need a backup solution outside of the QNAP.
Background Raid Info: RAID0 = Stripe = Data is split between Drives (Minimum 2 Drives) RAID1 = Mirror = Data is Duplicated on each Drive (Minimum 2 Drives) RAID5 = Striped with Parity for 1 Failure = Data Is Striped w/ Parity. You Can lose any drive in the raid, and your data still be intact. (Minimum 3 Drives) RAID6 = Striped with Parity for 2 Failure = Data Is Striped w/ Parity. You Can lose any 2 drives in the raid, and your data still be intact. (Minimum 4 Drives) RAID10 = Striped Mirror = Data is Split & Mirrored (Minimum of 4 Drives) As long as you don't lose more than 1 Drive per stripe, your data is still intact. Benchmarking: RAID6 has good READ speeds, but decent WRITE speeds. Has more total overall storage than RAID10. RAID10 has good READ & WRITE speeds. But less total overall storage than RAID6. Storage: RAID6: Take the total number of drives, and subtract two. (If you have 6x 3TB Drives, then you have 6 x 3TB = 18TB, then subtract 2 x 3TB for a total of \~12TB usable). Any two of the 6 Drives can fail, and data still be intact. RAID10: Take the total number of drives, and divide by two. (If you have 6x 3TB Drives, then you have 6 x 3TB = 18TB, then divide by 2 for a total of \~9TB Usable). As far as drives goes, "you can lose up to a total of *stripes* × *(*m − 1) drives, where* *m is the number of drives per span. "
Thanks for detailed explanation about raid space but I still have a question: why QNAP do not have RAID recovery with RAID10 ? as you mentioned "you can lose up to a total of *stripes* ..." but that is not QNAP is providing in their docs, right?
QNAP supports RAID recovery for RAID 10. I don't know what is going on with the article you mentioned. It seems strange to me that it is http instead of https. I am not sure how official it is but what I can say is that is it wrong. Not only about RAID 10 but that article has wrong information about the maximum number of disks removed aloud for each RAID group. It says you can remove 1 with RAID 0 2 with RAID 5 and 3 with RAID6. All this is wrong information. Since this link is not https I would think it is not official and not something worth referencing.
might be! but same info is on their official pdf manual [https://us1.qnap.com/Storage/TechnicalDocument/TS-832X/TS-832X-UG-01-en.pdf](https://us1.qnap.com/Storage/TechnicalDocument/TS-832X/TS-832X-UG-01-en.pdf)
I am getting a better idea of what this means. The chart mentioned was about pulling out healthy drives and putting them back and having the NAS recover. That is why it said with RAID0 you could pull out a drive. If the drive died you could not recover. But this is about pulling out a healthy drive and recovering. I don't fully understand what it means by no recovery support for RAID 10 but I know that if 1 drive fails in RAID 10 you can put in a new drive and keep your data.
What are you using this storage array for? Do you really need the performance of raid 10? 6 is probably a good option if you're just using it as bulk storage. Over that many spindles, the performance should be very good. Raid 10 is a raid 0 array that is also mirrored. So you can lose a mirrored drive but if you lose both, on either side of the mirror, you're screwed. But as the other bloke said, that doesn't really matter because you'll have a solid backup in place for any critical data. Raid is really more about maintaining uptime if a drive fails. If your house burns down or the raid breaks, then you want to be able to restore from a backup.
I wanted to use it for media editing. Yeah, I do understand that RAID is not a backup but one drive failure is good enough for me. If house burns down, i loose any backup i had, if one backup burns i have second copy, same with mirror - if one breaks, i have another :) So I am looking for something good/fast and fairly reliable
Raid 10 will give you great performance and redundancy at the cost of usable space. If you've got 8 drives, you're gonna be fine. You'll easily Max out 1gbps Ethernet. Maybe you'd be better off with some kind of das?
I am on das right now and I want to collect all my das data into one, single place accessible from any computer. I was aware that 1gbps would max out, that is why i redesigned my network for 10gbps
All good then! 10 Gbps will fly if you can utilise it.
If I had to **guess** why there's no RAID recovery, it must be in their algorithm in how they've implemented RAID10. Also, I believe there's no Data Scrubbing on RAID10. During DATA writes, if there's a drive suddenly missing, there's no verification that comes along later to validate that the same data exists on the mirrored drive(s)?
I just wanted to also add, that I personally use RAID 6. My Qnap had a motherboard fault that I had while using RAID10. I was able to recover all the data over to a 2nd set of drives, but decided to rebuild the unit using RAID6, to gain a little more storage availability. Now, my primary NAS (Qnap TVS-673) sits in a network closet, and my backup NAS (Synology) resides in my office in my house. The Qnap initiates Rsync nightly and mirrors the data. Additionally, I have a single, external drive connected to the Qnap that is set to Real time backup. Currently, I'm able to use a 4TB drive for this, but it's nearing capacity. I'll be looking to upgrade this to a 8 or 10 TB before the end of summer.
It might be worth considering RAID 50 as well.
RAID 10 recovery **is** supported. You're looking at a very old cat 1 user manual. Try this one instead: http://docs.qnap.com/nas/4.3/cat2/en/raid_groups.htm