We are in the process of moving our (direct attached) storage systems to an iSCSI based consolidate storage and we have come up with this interesting question: where should we place LVM processing? Let me explain.
We are configuring a consolidated storage system that is based on the three level methodology ie storage, filer, application server. That essentially separates storage devices from file-systems. The storage is based (among others) by DELL systems running CentOS providing iSCSI devices to the filers. The filers "consume" iSCSI storage by providing NFS/CIFS/etc file-systems to the application servers. Storage devices provide also iSCSI devices to the virtual hosts (KVM) that directly make use of it in the form of VGs for their virtual machines.
Here is the question? Where do we place LVM processing? In other words should we partition (ie create PP/VG/LV with LVM on the storage servers or on the Filers/VMhosts?
Our initial approach was to postpone as much of the processing/translation of storage (LVM and file-systems) to upper level hosts (filers/application servers) since there will be several of those and only few storage servers. In this way we distribute processing more effectively. Are we right? Are we grossly doing something wrong? thanks.