Hi Jens, Read Inline.. > Some of my Questions: > > 1.) When requesting a file, is the whole file retrieved or only a portion > of > the file? > Gluster has 1-1 mapping between client side posix calls to server side posix calls. ie, when a open is called on client mount point, it will be translated to a open on server side (where the file actually resides). Answer for your question will be you will get the portion of file you requested for, and not whole file. > 2.) Are random File accesses supported? > Yes. But, considering scenario in case of Databases, which is, random file accesses with query(read) for very small blocks, network delay and context switch delays involved will make the performance suffer. > 3.) How does cluster internally Workd when the Database (liek MySQL) create > a large file and then accesses this file? Does Cluster shomehow operate on > a > "Block Level"? How will an index-scan be translated in reagards how gluster > will access the data on the remote system? > > As I told in case of 1, Gluster will do 1-1 operation which is done @ the mount point over the server, hence the main issue again will be latency of the network in all these operations. > I am very thankfull for any information (also links...) that help me to > understand how gluster internally handles "file accesses" . > > Lets be clear on what 'file accesses' means. I am taking it as 'read' (considering its a database and there will be lot of queries), but there are multiple system calls which can mean the same with respect to filesystem, like, access(), lookup(), stat(), open()... Regards, Amar
