Hi,
we want to upgrade our infrastructure and are considering renting two different types of server by a provider:
- A: one is with 80 GB SSD (and 12 GB memory) http://www.ovh.co.uk/products/eg_ssd.xml - B: the other with 750 GB SATA2 (and 8 GB memory). http://www.ovh.co.uk/products/eg_best_of.xml
The target infrastructure will host: - a few public web sites (PHP / MySQL) - a development infrastructure (subversion, bugzilla, automated builds)
This will use KVM virtualization with Cent OS 5.4 hosts and guests.
On the long run we will probably rent quite a few of type B depending on our needs of space and computing power.
My question is whether it is worth using one of type A (with SSD drives) in order to host the critical data such as the web sites and the subversion repository (critical in the sense that these services should be fast, always available, and the related data as safe as possible).
This critical server will be more read oriented than write. We will probably use a hardware RAID 1 with battery backed unit on it.
My understanding is that SSD are much much faster. Is it really true in the real world?
Are SSD drives also safer? (that is, less likely to crash under load) Or to the contrary?
I have read/heard conflicting opinions so far and I'll be happy to hear opinions/experiences on SSD drives in a server settings from people on the list. More general comments about our plans are always welcome of course!
Cheers,
Mathieu
PS: we will actually rent them in France, but I put links to the equivalent in Britain in order to have the description in English. For reference and for the French-speaking people, here are the actual servers we consider: http://www.ovh.com/fr/produits/eg_ssd.xml http://www.ovh.com/fr/produits/eg_best_of.xml (they are exactly the same)
<snip>
The real question is how many hits/hour you expect. I interviewed last year at a major advertiser... but (and I'm trying to remember from last May) they were getting hundreds of millions of hits per day.
For tens or hundreds of thousands, the normal drives are more than fine. That, of course, also depends on the sites: in early '03, I looked at a small site, and the guy's web pages took *forever* to load... but that was because he'd taken photos of his work, and each page had something like four or six photos, each of which was 1.5M-4M. <snip>
The enterprise grade ones. And, if they're not enterprise grade, and the provider's cheaping out and using the kind sold in stores, they're not as reliable. If this is that important, I trust you're looking at SLA in the contract.
mark
On Tue, Jan 12, 2010 at 7:30 AM, Mathieu Baudier mbaudier@argeo.org wrote:
It's too early to start putting Flash-based SSDs in servers unless you have a really specific need. Based on you description above, this does not sound like a hugely high-performance I/O server. I suggest you look into 15k RPM disk drives setup in a RAID10 configuration. That will get you the most speed. Additionally, the Linux IO system uses RAM extensively for caching, so you'll be getting the benefit of that anyway.
Mathieu Baudier wrote:
Go with 10/15k RPM SAS, not Intel SSD or SATA if you want best availability. Intel SSDs have had firmware issues since they came out, I doubt we've seen the end of firmware changes on them.
If you want even higher availability go with a better provider, this is a good cloud hosting provider which uses VMware and high availability storage -
http://www.terremark.com/technology-platform/nap-data-centers.aspx
http://vcloudexpress.terremark.com/
Looks like they have 4 locations in Europe, I haven't used them myself but went through a presentation for them last year very impressive, though they are pricey. If you have simple requirements it's probably not bad though(will be a few times more $ than the hosting provider your looking at, but hey you wanted fast, always available, and safe, those aren't cheap). You can provision machines yourself, manage a remote firewall, and load balancers from their web UI.
nate
We don't have extremely high load requirements. This is first and foremost a development infrastructure with a public part for our free software products. So we don't expect very high volume on it in the foreseeable future. Our idea is more that we are ready to invest a bit more in the hardware to be on the safe side.
We have been running our infrastructure for the last three years on a cheap server with 1GB memory and on a Linux so old that I cannot even tell here for security reasons (and a bit shame as well probably...) We had one single crash during the three years (probably because I kept everything very simple) and it is only for a few months that we start feeling that the development of our activity requires something bigger.
I would also say that it is more important for us to have control over the whole stack than to have optimal performance. And this whole stack has to be free software (which excludes VMware I guess).
But I really appreciate your suggestions, and if anybody has ideas of other good providers in the European Union, I'm very interested!!
Quoting Mathieu Baudier mbaudier@argeo.org:
Well, if you really want to buy fast and expensive ssd from intel then just do it, but do not go with cheap ssds.
-- Eero
Well, if you really want to buy fast and expensive ssd from intel then just do it, but do not go with cheap ssds.
Ok, I see your point (also putting it in relation with other helpful comments from this thread): you mean that the SSD drives that this provider offers: http://www.intel.com/design/flash/nand/mainstream/index.htm are mainstream SSD (not enterprise) and thus are likely to bring me problems.
Thanks!
Mathieu Baudier wrote:
At this point I would say any SSD that is not from STEC is not "enterprise", it seems most vendors at least for the moment have partnered with STEC for their enterprise SSD needs.
While I don't think you can boot from it, FusionIO is probably decent quality as well, and screaming performance.
nate
Hi,
The Intel SSD are fast but have a history of firmware problems. So I wouldn't suggest using them on a mission critical data. Personally I think asking for more RAM on the SATA server would do more for performance especially since you are going to be running several VM.
Just my noobish 2 cents' worth.
I concur that I would not use them on anything important.
On Thu, Jan 14, 2010 at 12:13 AM, Noob Centos Admin centos.admin@gmail.comwrote: