Hi Jörg, I'm the author of those slides, and that statement, even when taken out of context starts with "Prefer", I don't think I need to explain what prefer means, but just in case ... Using JBOD will be your safest bet as opposed to using something like RAID / SAN/ NAS unless you really know what you're doing. I never said DON'T EVER use RAID or even SAN|NAS, just "prefer" JBOD.
I do agree with your assessment of RAID 0 below, but do remember that, that one statement was taken out of context, for full context I suggest you go through the whole slide deck and better yet the whole talk whose video was posted on elasticsearch site. I even made a point about some of my recommendations not being applicable to cloud deployments etc. As to your point about simplification of NAS|SAN, that's the whole point of presenting to a wide audience, one simplifies things such that they can be applied to majority of the cases, and not concentrate on esoteric deployments :). As to local gateway, that's the only one ES recommends now, the shared FS, HDFS, S3 gateways were long deprecated. FWIW I fully agree with your statement on taking control over complete hardware setup, heck there's a full slide in there dedicated to this point, titled 'Know your platform'. At the end of the day, there's no single silver bullet, everyone will have to evaluate what works best for their situation, what worked for us may not work well for others. It would be indeed very naive to take my slides as laws, they are more or less pointers worth exploring. Some may work for you some won't. They worked fairly well for us. I might sound a bit defensive here, but hey we did build that cluster and we're nearing a Trillion documents in it, so I guess we must be doing something right :). Bhaskar On Saturday, December 13, 2014 at 10:48:55 AM UTC-5, Jörg Prante wrote: > > The statement is related to performance and I can't agree with it. You can > easily build a RAID 0 system which has massive I/O throughput performance > and is superior to JBOD, because RAID striping does not slow things down, > it is as always as much as fast than a single drive and in most RAID levels > it is much faster. > > In the past, RAID was invented for mirroring cheap and error-prone spindle > disk arrays, while mirrors increase costs but decrease fault probability. > > With Elasticsearch, the decision is if you still want to handle disk > faults by drive redundancy (RAID) and all other hardware faults like power > outages by server downtime. This is just a matter of organization and of > cost. I would suggest from my experience: take control over your complete > hardware setup, equip your systems with expensive SAS2 (or even better) > controllers with RAID 0 to reduce cost and maximize performance, and handle > all kind of hardware faults by server downtime, because ES replica level > > 0 allows that. > > There is also a simplification of SAN/NAS in the statement but that is a > different discussion. Never use SAN/NAS for ES local gateway. > > Jörg > > On Fri, Dec 12, 2014 at 7:28 PM, Elvar Böðvarsson <[email protected] > <javascript:>> wrote: >> >> >> Second, "Prefer JBODs for data disks over RAID, SAN/NAS", would be ok, >> maybe then to be safe go with 2x replicas, goes well with having 3x nodes >> >> -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/elasticsearch/d0fa5e9c-2658-4fef-a9ad-ea83873a8f28%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
