On Tue, Jan 12, 2010 at 7:30 AM, Mathieu Baudier <mbaudier at 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.