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135TB for $7,384 - Backblaze Pod 2.0

zdnet.com

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Re: 135TB for $7,384 - Backblaze Pod 2.0

#2
Direct link to Backblaze's blog post: http://blog.backblaze.com/2011/07/20/petabytes-on-a-budget-v...

They got rid of the PCI bottleneck by switching to PCIe, a bottleneck which surprised me when they designed version 1.0 of their pod. They could have gone PCIe at the time, I maintain http://blog.zorinaq.com/?e=10 and they were SATA controllers at the time that met their technical requirements (nr. of ports, Linux support, etc).

Re: 135TB for $7,384 - Backblaze Pod 2.0

#3
The diagram of the Cost of a Petabyte is very interesting if it is true. It demonstrates the profitability of some SaaS models for selling what is a straight commodity.

However it seems in contradiction to the AWS, Rackspace model, which is a race to the bottom in that there are many competitors and they are selling a commodity (independent of the other high value services they are selling). There is some threshold of volume that is key in order to make money in that space.

Re: 135TB for $7,384 - Backblaze Pod 2.0

#6
What's the RAID config of these boxes? 45 drives, 4 controllers, and a 16TB volume limitation from ext4. Please share if you know!

--edit--

I know it's RAID6 from the article. What I'm wondering is, how many drives in an array? How many arrays per box?

Re: 135TB for $7,384 - Backblaze Pod 2.0

#7
Does anyone know if Backblaze will ever support Linux? I've wanted to use their service for a while now, but their lack of Linux support has being a big turn down, and I don't think they have made any change in their statements regarding this 'issue'.

Re: 135TB for $7,384 - Backblaze Pod 2.0

#9
post #6

What's the RAID config of these boxes? 45 drives, 4 controllers, and a 16TB volume limitation from ext4. Please share if you know! --edit-- I know it's RAID6 from the article. What I'm wondering is, how many drives in an array? How many arrays per box?

At the lowest level there are three RAID groups in each pod. Each RAID group is made of 15 drives configured in software RAID 6 with 2 parity drives. This means you can lose 2 dives and the data is entirely safe and intact. If 3 or more drives completely fail simultaneously (not just pop out of the RAID group or power down, but where that drive is lost forever, like it will never power up again) you will lose at least some of the data on that RAID group. Layered on top of the 15 drive RAID group is LVM. The specifics of the LVM config are there is one PV (Physical Volume) spanning the 15 drives, then on top of that are one VG (Volume Group) spanning the same exact 15 drives. Then on top of that are as many LV (Logical Volumes) as it takes to keep each logical volume under the ext4 limit of 16 TB. With 3 TB Hitachi drives, there are 3 separate LV on top of the same exact 15 drives. Finally, there is one ext4 file system sitting on top of each of the LV (one to one with the LV). Disclaimer: I work at Backblaze, but datacenter and pods aren't my main area of focus.

Re: 135TB for $7,384 - Backblaze Pod 2.0

#10
post #6

What's the RAID config of these boxes? 45 drives, 4 controllers, and a 16TB volume limitation from ext4. Please share if you know! --edit-- I know it's RAID6 from the article. What I'm wondering is, how many drives in an array? How many arrays per box?

At the lowest level there are three RAID groups in each pod. Each RAID group is made of 15 drives configured in software RAID 6 with 2 parity drives. This means you can lose 2 dives and the data is entirely safe and intact. If 3 or more drives completely fail simultaneously (not just pop out of the RAID group or power down, but where that drive is lost forever, like it will never power up again) you will lose at leas…

Thanks!
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