Instead of caching software, why not make a hybrid setup?
Posted: Sat Jun 02, 2012 9:58 pm
Regarding this video and a few more following that:
http://www.youtube.com/watch?v=DBFoz_xx ... ature=plcp
They were talking about how SSD should be used as a caching or used as a tier. They make some good points all around on both sides. They bring up cost and performance and how easy will this be setup base off how much control is needed from the user and applcation.
viewtopic.php?f=26&t=1215 Page 1
One of the points we made before was that SSD at one point will be cheap enough that having an SSD as cache would be pointless as the HDD could be totally replaced by the SSD. This bring up that SSD maybe shouldn't be used as caching, instead, SSD should maybe used into a hybrid caching/tier technology instead.
What do I mean by a hybrid caching/tier technology? Simly put, the FC software will smartly move data that is constinly access to faster medium base on the mediums' speed instead. This way as SSD becomes cheaper and faster, replaceing older SSD and HDD will be simpler and easyer also as that data will be freed and moved to the faster mediums as more rooms becomes available. This alone will increase read speeds with the L1 and L2 working away gathering and moving information that will speed up applcations load and performance. Write also would see a performances form that fact that disk head will be free up simply by taking the read load off the drive.
That sounds great you might say, but what if I switch off HDD and on to SSD instead? What speeds would I see from that? Well, FC would be able to still use its L1 to cache data's Read commands and load them up faster. Why reads only? As talk about from the Link above on many pages, RAM is very risky as a write mediums. If power goes out, system crashes, or hardware failer, that data would be lost forever where read data would still be ok as that data was just a copy of it self. FC could still keep writes but as an advance option to still give the users the power of choice, but keep them from hurting themselves as bad if they don't know all the risk from turning it on. A warrnings would be poping up talking about the risk about these features and a bit more detailed how risky each feature could be.
It also would still be able to grade your SSD performance as each SSD might perform different than the other. For example, SandForce offers a perty nice all around speed up in terms of reads and writes, but Indexs(sp) offers even faster/better read speeds even if the write speeds are not that greate. FC would be able to finde the best way to setup that data to take advantage of the IOs of both by moving write data to the SandForce drive and mostly read data to the Index(s) drive instead without really having to know that SanForce or Index(s) was the controler.
Note this is a WIP, I just wanted a place to store my thought, so I could access it anywhere as I tend to move around a lot. The idea is for FC in a much later version. The idea came to me after watching the said video above and remembing haveing a talk with FC support about when SSD become cheap/faster enough FC might not work anymore. This option/thought would still give life to FC even if that happens. It would make FC a mid ground between the different type of stroage that is around in both customers and enterpise enviroments.
http://www.youtube.com/watch?v=DBFoz_xx ... ature=plcp
They were talking about how SSD should be used as a caching or used as a tier. They make some good points all around on both sides. They bring up cost and performance and how easy will this be setup base off how much control is needed from the user and applcation.
viewtopic.php?f=26&t=1215 Page 1
One of the points we made before was that SSD at one point will be cheap enough that having an SSD as cache would be pointless as the HDD could be totally replaced by the SSD. This bring up that SSD maybe shouldn't be used as caching, instead, SSD should maybe used into a hybrid caching/tier technology instead.
What do I mean by a hybrid caching/tier technology? Simly put, the FC software will smartly move data that is constinly access to faster medium base on the mediums' speed instead. This way as SSD becomes cheaper and faster, replaceing older SSD and HDD will be simpler and easyer also as that data will be freed and moved to the faster mediums as more rooms becomes available. This alone will increase read speeds with the L1 and L2 working away gathering and moving information that will speed up applcations load and performance. Write also would see a performances form that fact that disk head will be free up simply by taking the read load off the drive.
That sounds great you might say, but what if I switch off HDD and on to SSD instead? What speeds would I see from that? Well, FC would be able to still use its L1 to cache data's Read commands and load them up faster. Why reads only? As talk about from the Link above on many pages, RAM is very risky as a write mediums. If power goes out, system crashes, or hardware failer, that data would be lost forever where read data would still be ok as that data was just a copy of it self. FC could still keep writes but as an advance option to still give the users the power of choice, but keep them from hurting themselves as bad if they don't know all the risk from turning it on. A warrnings would be poping up talking about the risk about these features and a bit more detailed how risky each feature could be.
It also would still be able to grade your SSD performance as each SSD might perform different than the other. For example, SandForce offers a perty nice all around speed up in terms of reads and writes, but Indexs(sp) offers even faster/better read speeds even if the write speeds are not that greate. FC would be able to finde the best way to setup that data to take advantage of the IOs of both by moving write data to the SandForce drive and mostly read data to the Index(s) drive instead without really having to know that SanForce or Index(s) was the controler.
Note this is a WIP, I just wanted a place to store my thought, so I could access it anywhere as I tend to move around a lot. The idea is for FC in a much later version. The idea came to me after watching the said video above and remembing haveing a talk with FC support about when SSD become cheap/faster enough FC might not work anymore. This option/thought would still give life to FC even if that happens. It would make FC a mid ground between the different type of stroage that is around in both customers and enterpise enviroments.