On Tue, Jan 12, 2010 at 7:30 AM, Mathieu Baudier mbaudier@argeo.org wrote:
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)
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.