Help me choose a RAID option

Yaayuh!

Yaayuh!

Yaayuh!

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Going to be installing a NAS for Backup-to-disk and data archive. 24Tb in total spread over 12 drives.

Data integrity/protection is very important especially since we don't run a clustered environment so RAID-6 + hotspare or two is high on my list.
I will be using BE to backup quite a bit of data weekly and incrementally each night so i will still need the write speed. Along with that that data on the NAS will be backed up to tape so read speeds are also important.
I will be needing at least 16Tb but 18Tb would be good.

Given that information, what would you recommend?
 
RAID6 + Hotspare is the minimum you want these days, especially with such large disks. A hotspare is only there to start rebuilding the array in the event of a disk failure, so one is fine, two if you're super cautious.
With 12 disks, you will be giving up 6 of 24TB (with one hotspare), taking you to 18TB.
Then apply fomatting, and you end up at around 16.5TB of usable space.

RAID6 has fine read speeds.
The issue is write speeds. You effectively use 6 IOPs per write operation in RAID6.

It all sounds good fine, but test the write speeds to make sure they're acceptable for what you want to do with it.
 
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Like you said, RAID6 with 1 spare is about the best you're going to get. If the write speed isnt great, see if you can get a RAID50 option that fits, but with that you'll need an even amount of disks, so you'll have to have 2 hotspares or none. We use RAID50 for a simular setup (commvault library). Whatever option you chose, rebuild times are massive if the NAS is constantly being used, but you are writing to tape, so if the worse does happen during a rebuild at least you're covered.
 
Cheers guys for the input and confirming my current thoughts.
I would go for 2 hotspares as i am a little cautious, but as you've just pointed out, that'll bring me below the storage space minimum. However; as this is going to have to last 5 years and the company may allow an over spend on the IT budget because we're doing so well, i may look into a 16 drive chassis and weigh out the pros and cons.

The problem with the tape backup is that we only have 2x LTO 4 drives and a massaive amount of tapes, this is for a custom offsite storage plan of critical data at the moment so will be completely changed for this new setup i'm implementing. Ideally i'd like a tape library/autoloader, i'm working on that one...
 
Erm, perhaps I'm missing the obvious here but why recommend a tape library when the OP is looking at a NAS for a D2D backup solution? A quick Google reckons that the i500 library with no tape drives is 11,000 USD+, so perhaps a bit pricey too?
 
#Chri5# said:
Erm, perhaps I'm missing the obvious here but why recommend a tape library when the OP is looking at a NAS for a D2D backup solution? A quick Google reckons that the i500 library with no tape drives is 11,000 USD+, so perhaps a bit pricey too?
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I need to replace the offsite storage solution as well at some point when money allows. It's a different project.

However, i am contacting a few suppliers regarding cloud storage, around 50Tb would cover us very nicely for complete backups and archives, everything and some.
Just waiting on some quotes.
Does anyone have any Cloud storage experienced from the client side? I'd like to know what the access, administration and restore solutions are like.
 
Yamahahahahaha said:
Evault offer a hybrid on-site / cloud backup and DR solution.
It's not cheap, but it's worth having a look.
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This looks promising, thanks for that, i'll give them an email.

I got quoted £12,500 A MONTH earlier from another company...i just started laughing at them. They clearly didn't take any notice of the fact that we're a small company of only 50 users..
 
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