61–70 of 106 posts
What happens when one of the PSU's fails catastrophically, pushing a big electrical surge through the hard disks, frying half of them? I didn't see anything in here that discusses that eventuality? And when you have that many servers, it IS going to happen at some point...
What a pity, I'd like to have a way to store just a encrypted backup directly (via ssh) instead of installing a app which crawls my system. Oh did I mention I use Linux? sign Does somebody know any other company which provides this solution? I don't trust other people to crawl my system and to "encrypt" it for me. EDIT: Added Question
rsync does exactly what you're looking for. You can also pipe it over SSH encyption on the wire. type "man rsync" at a shell for a description of how.
Earlier quoted context omitted.
Interesting, but Amazon doesn't guarantee most of those things. They guarantee a 99.99% uptime, but that isn't counting a complete datacenter failure. In fact, it sounds to me as if they have a similar set up to the backblaze people. 99.99% uptime means roughly 1 hour per year of downtime. I don't know what the specific failure rates on the components are, but it seems reasonable that A) the data drives are hot-swapp…
Re. geographical redundancy, see comment http://news.ycombinator.com/item?id=422574 : "Amazon keeps at least 3 copies of your data (which is what you need for high reliability) in at least 2 different geographical locations. " I can't find the original source supporting that statement, but I also know it to be true based on direct contact with AWS team. (I'm using AWS since private alpha of EC2 in 2005)
In addition, looking at the actual S3 contract, they're really only guaranteeing at 99.9% uptime, which allows for up to 8 hours of downtime a year, more than enough to completely re-build the outer server once a year, as long as they can keep the data intact (which they seem more than capable of with their setup, once again assuming their data center is not completely destroyed).
I wonder about the single point of failure posed by the power supplies. One failed box is not a big deal (since I assume the data is replicated over several). But, what if they get a bad batch of supplies and see a relatively high failure rate? I wonder how high a power supply failure rate they can handle. The need to stagger the power on of the two supplies poses a problem. What if power to a data center is lost? Wh…
You should only use 75% of the rated capacity of a circuit, which means you have enough power to turn them all on at once. some of the more expensive managed power supplies also support a staggered power on after power fail. But I don't worry about it; only using 75% of the power circuit solves that problem for me.
Addressing this would require a little bit of design, but the problem is relatively simple. If they wanted to get fancy, they could add a chaining feature--pods on the same circuit would be connected together so that they'd power on serially. This would get away from their goal of using off-the-shelf parts. It is, as with many things, an engineering trade-off.
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Thinking the exact same thing! While technology isn't more than any typical hacker can slap together in their apartment (minus maybe the case fab), I think the application is ingenious and the full blog post about it, like dmillar, pointed out is rather awe-inspiring. And I was all happy because my new Core i7 box has 2TB of space and 6GB of ram... sigh That being said - did seagate ever fix their firmware issue on t…
Yes, they did a firmware update. Here is one article that talks about it: http://www.tomshardware.com/news/seagate-barracuda-1.5TB-fre...
Seems dangerous to source all your hardware from one vendor over a small timeframe. Would be nice to have some redundancy over manufacturers too.
Earlier quoted context omitted.
You should only use 75% of the rated capacity of a circuit, which means you have enough power to turn them all on at once. some of the more expensive managed power supplies also support a staggered power on after power fail. But I don't worry about it; only using 75% of the power circuit solves that problem for me.
Unfortunately, using 75% of the rated capacity may not be enough to handle the inrush. The article discusses this point, "...if you power up both PSUs at the same time, it can draw a large (14 amp) spike of 120V power from the socket." That would mean one pod per 20A circuit. Ugh. In normal operating conditions, a 5.6A max load would allow three pods per circuit. Addressing this would require a little bit of design,…
from there it would be easy enough to have an automated process turn on servers one at a time.
I always thought it was best to focus on what I did best (application software) and leave the infostructure to others. Until I saw this: Raw Drives $81,000 Backblaze $117,000 Dell $826,000 Sun $1,000,000 NetApp $1,714,000 Amazon $2,806,000 EMC $2,860,000 I had no idea. Kinda makes one rethink what business they want to be in.
As a sysadmin for organizations of different sizes, I've been acutely aware of this for quite some time. The more painful corollary is that, even if one measures not by total storage but by performance (a more critical aspect of, e.g., databases), the prices are still an order of magnitude or two apart. I would argue that the reason "No One Sells Cheap Storage" in the backup/archive sense is that there isn't enough d…
Personally, I'm working on a system whereby I just fill up otherwise unused slots on my chassis and use that for backup. The system isn't done yet, but I've got 6 disks out there waiting for me to figure it out.
I always thought it was best to focus on what I did best (application software) and leave the infostructure to others. Until I saw this: Raw Drives $81,000 Backblaze $117,000 Dell $826,000 Sun $1,000,000 NetApp $1,714,000 Amazon $2,806,000 EMC $2,860,000 I had no idea. Kinda makes one rethink what business they want to be in.
As a sysadmin for organizations of different sizes, I've been acutely aware of this for quite some time. The more painful corollary is that, even if one measures not by total storage but by performance (a more critical aspect of, e.g., databases), the prices are still an order of magnitude or two apart. I would argue that the reason "No One Sells Cheap Storage" in the backup/archive sense is that there isn't enough d…
I don't think a single SAS card can support more than 128 (or maybe 256 if you're lucky) disks. This doesn't affect your math much, but I wouldn't want someone to try this at home and be disappointed. If you're not willing to build a custom case and don't feel like suffering the vagaries of SATA expanders, LSI SAS cards plus Supermicro JBODs are the way to go.
This is unbelievably awesome. Can you imagine what we could achieve if every company had this level of transparency?
Thinking the exact same thing! While technology isn't more than any typical hacker can slap together in their apartment (minus maybe the case fab), I think the application is ingenious and the full blog post about it, like dmillar, pointed out is rather awe-inspiring. And I was all happy because my new Core i7 box has 2TB of space and 6GB of ram... sigh That being said - did seagate ever fix their firmware issue on t…
I'm sure the backblaze folks have built something that handles that sort of thing into the system, but just saying; it's something you have to think about before you slap consumer drives into a raid that needs to keep working when one drive fails.
What a pity, I'd like to have a way to store just a encrypted backup directly (via ssh) instead of installing a app which crawls my system. Oh did I mention I use Linux? sign Does somebody know any other company which provides this solution? I don't trust other people to crawl my system and to "encrypt" it for me. EDIT: Added Question