Sun engineer responds to the Backblaze "Petabytes on a budget" design
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Re: Sun engineer responds to the Backblaze "Petabytes on a budget" design
#2That's a pretty weird analysis, comparing a system that is special purpose with a general purpose one.
He's concentrating on disk-to-board throughput, but this being network attached storage on a LAN, using the motherboards' single ethernet port the amount of data read or written to those drives per second will never exceed 1 Gbit/second anyway.
I agree with the reliability analysis though, backblaze seems to be on fairly thin ice there.
Still, it seems to work for backblaze, I'm taking it as read that they've lived through a bunch of drive failures by now and they seem to still be in business.
Re: Sun engineer responds to the Backblaze "Petabytes on a budget" design
#3I think everyone agrees the Backblaze (bb) has no performance - and that's fine.
But a lot of his complaints are about reliability, and thats kind of a moot point since Backblaze (and anyone sane) stores every piece of data on at least two (and ideally 3 or more) separate bbs. I would argue if you don't need performance (i.e., no huge database), but you do need a lot of space, you're better off just setting up two 'mirrored' bbs (so that when one goes down, the other takes over) than almost any 'enterprise' solution.
He does have a point about ZFS though - I'm sure at that kind of scale eventually the RAID 5/6 write-hole is going to bite you in the ass.
Re: Sun engineer responds to the Backblaze "Petabytes on a budget" design
#4That's a pretty weird analysis, comparing a system that is special purpose with a general purpose one. He's concentrating on disk-to-board throughput, but this being network attached storage on a LAN, using the motherboards' single ethernet port the amount of data read or written to those drives per second will never exceed 1 Gbit/second anyway. I agree with the reliability analysis though, backblaze seems to be on f…
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Re: Sun engineer responds to the Backblaze "Petabytes on a budget" design
#5That's a pretty weird analysis, comparing a system that is special purpose with a general purpose one. He's concentrating on disk-to-board throughput, but this being network attached storage on a LAN, using the motherboards' single ethernet port the amount of data read or written to those drives per second will never exceed 1 Gbit/second anyway. I agree with the reliability analysis though, backblaze seems to be on f…
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> Given the reliability info he cites, the fact that backblaze is still in business must mean their usage-to-storage ratio is small.
No, it probably means that they get their reliability at a different level, such as simply storing the data on a number of machines. Systems like glusterfs make this completely transparant.
Re: Sun engineer responds to the Backblaze "Petabytes on a budget" design
#6Fascinating read, and its nice to see he brought up a lot of the concerns that were mentioned here. A few things that I noticed:
He mentioned that 1 Disk uses 120 MB/s, so 5 of them is 600 MB/s. He then says that converts to 6 GB/s. Now, I'm not all that familiar with speeds, but I know 1000 MB is 1 GB, so shouldn't 600 MB/s be .6 GB/s?
Other than that, he raised a number of valid points. The Backblaze system is NOT general purpose. Its designed to take a bunch of data (Backups) and hold on to it for as long as possible. In that situation you don't need high Throughput, or even all that reliable hardware. Once the drives are full, their usage will drop, and as long as the RAID can be kept up to keep the data secure, as long as costs stay down they're fine to keep replacing hardware.
One thing of note, and something I never saw in the Backblaze article: Their service promises to hold your data for 50 years. Assuming that one of their pods is filled, what is the estimated cost to keep that data over the course of 50 years? I would assume they calculated that out, and that the data showed to go with the consumer grade parts, but I would really like to see the numbers.
Re: Sun engineer responds to the Backblaze "Petabytes on a budget" design
#7Ok I must be missing something. Everyone is knocking this backblaze thing because it doesnt do ZFS or because it is not a "super duper high end san replacement" or because the components are not rated for enterprise level work. It seems to me that a company whose product is personal and small business backups does not need any of those things. They have software to do mirroring. Why would they need any fast network filesystems if all data comes and goes via the internet? Will the hard drives see that much data I/O, or will they mostly just fill up and sit idling with the very occasional read for restore (i strongly suspect the later)[1].
Of course on the other hand, there are the poeple touting it as the end all be all, a solution to kill NetApp.
I guess what Im wondering is: how did so many people get the idea that this article about a specific solution to a specific problem was actually some sort of general purpose solution attacking all the big name people? What am I missing?
[1]A huge chunk of this article is about the hard drives and PSUs not being enterprise ready, but for an enterprise load, but I just don't see it. I bet a lot of these boxes run idle a large chunk of the time. I have 10 year old desktop hard drives running just fine in a file server, because it has a similar load: mostly idle most of the time.
Re: Sun engineer responds to the Backblaze "Petabytes on a budget" design
#8That's a pretty weird analysis, comparing a system that is special purpose with a general purpose one. He's concentrating on disk-to-board throughput, but this being network attached storage on a LAN, using the motherboards' single ethernet port the amount of data read or written to those drives per second will never exceed 1 Gbit/second anyway. I agree with the reliability analysis though, backblaze seems to be on f…
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Re: Sun engineer responds to the Backblaze "Petabytes on a budget" design
#9That's a pretty weird analysis, comparing a system that is special purpose with a general purpose one. He's concentrating on disk-to-board throughput, but this being network attached storage on a LAN, using the motherboards' single ethernet port the amount of data read or written to those drives per second will never exceed 1 Gbit/second anyway. I agree with the reliability analysis though, backblaze seems to be on f…
"That's a pretty weird analysis, comparing a system that is special purpose with a general purpose one."
I think that's why he says right at the beginning:
This device is that cheap because it cuts
several corners. That's okay for them. But
for general purpose this creates problems.
I want to share my concerns just to show you,
that you can't compare this to a X4540 device.Re: Sun engineer responds to the Backblaze "Petabytes on a budget" design
#10Fascinating read, and its nice to see he brought up a lot of the concerns that were mentioned here. A few things that I noticed: He mentioned that 1 Disk uses 120 MB/s, so 5 of them is 600 MB/s. He then says that converts to 6 GB/s. Now, I'm not all that familiar with speeds, but I know 1000 MB is 1 GB, so shouldn't 600 MB/s be .6 GB/s? Other than that, he raised a number of valid points. The Backblaze system is NOT…
You got confused about the GB/s because he uses the capital "B" at some point where it should have been the smaller 'b' for bits, not bytes. So, 600 MB/s is 600*8 = 4800 Mbps.
I hope that clears it up.
Please note that this is the guys private blog, he definitely does not speak for Sun in that spot and to label the article "SUN Engineer responds" makes it seem like the response is an official one but it very clearly isn't. The text is full of other mistakes as well.