Thanks Beck :)  allow_multi_map option enables you to present the same volume to multiple hosts, but you still need that the host itself to understand that a volume is shared with other hosts and to have some mechanism to provide file system integrity in this scenario.  For example, VMware has its VMFS, Microsoft has Cluster services, or more recently CSV.  You should check how to enable at kvm and your Linux distribution similar capabilities.
Hi All,   I'm a beginner of ScaleIO. I had tried to map a virtual volume to multiple Hosts for KVM-Based VDI shared-storage purpose and  executed scli commands like below: [MDM] > scli --login --username admin --password mypasswd > scli --add_volume --protection_domain_name default --storage_pool_name default --size_gb 200 --volume_name vol_1 > scli --map_volume_to_sdc --volume_name vol_1 --sdc_ip 192.168.100.10 --allow_multi_map > scli --map_volume_to_sdc --volume_name vol_1 --sdc_ip 192.168.100.20 --allow_multi_map   [SDC-192.168.100.10: vol_1=>/dev/scinia]  > mkfs.ext4 /dev/scinia > mkdir /mnt/vm-pool01 > mount /dev/scinia /mnt/vm-pool01   [SDC-192.168.100.20: vol_1=>/dev/scinia]  > mkdir /mnt/vm-pool01 > mount /dev/scinia /mnt/vm-pool01   , however the contains (files) under /mnt/vm-pool01 cannot sync between hosts when some files had been modified on one side! Files that been generated at /mnt/vm-pool01 on Host 192.168.100.10 cannot be listed  at 192.168.100.20's /mnt/vm-pool01?   I am confused about the appropriate usage of "--allow_multi_map"!? And i have no idea how to approach the shared-storage major objective?   All suggestions and guidance are welcome.   Many thanks, Beck
How to approach the KVM-Based VDI shared-storage scenario with ScaleIO?