Hello,
i do not have any experience with ESX5.0i and vSphere5.0, but I need some help for planning a hardware infrastructure. So, I try to approach the problem from the hardware side (with the background I have), but I dont know much about ESX5.0i / vSphere5.0 capabilities and if it can do what I want it to do.
I know there there are High Availability setups, with two synchronous servers (nodes), which are connected to one data storage. Typicalliy, in such a HA setup, each server has two SAS controllers, which communicate to an external data storage which has a dual controller SAS. It´s the typical dual domain / dual path setup. In case one server (or one controller or one cable) fails, the other server continues all tasks. It´s a master/slave concept that is used here in the disk driver which determines which server is allowed to write on the RAID, and which server is not allowed. Personally, I do not really like this concept with two servers and one data storage, because if the one data storage fails, it´s basically game over. So a setup with two servers and two data storages looks better to me.
In addition to that, as the setup with the dual path is kinda complex, and the special pricy hardware for it is only provided by very few companies like IBM or HP, I like to know if it is possible to build two identical servers from standard parts, and achieve nearly the same level of HA (the above mentioned concept of 2 servers and 2 data storages).
Let´s assume we have two servers, with enough memory, and each has 10 disks in a Raid for that.
Questions:
1.) Is it possible to use ESX5.0i / vSphere 5.0 in a HA setup, so if one server fails, the other one continues the tasks? From the standard HA setup described above (2 servers, 1 storage), I know it´s generally possible, but my question is if it also works with 2 servers and 2 storages (each server has its own storage).
2.) If one server fails, for example by hardware malfuction, and the server is repaired and restarted the next day, how does this system synchronize again with the other functional system? The data on the storage is not synced anymored, so i assume this needs to be done first on the fly, and secondly then the server needs to be put in a state that it can start doing the same things as the first server again to provide fault tolerance. The question I have is: how does it synchronize the data storages on the two computers? A standard backup solution wouldnt help much as the source data also changes during the backup process, so I assume the only way would be if ESX / vSphere has some functions for that.
A few keywords, a brief explanation, or a link would be of great help for me to understand how the this can be solved.