What's the meaning of :
that's absolutely wrong. Gluster doesn't need to do a full sync (and also it doesn't use rsync at all except for geo-replication) after a brick failure. Only missing files from that bricks are synced back, like in every other replicated system. Even in a RAID, if you loose a disk, you have to sync the whole disk.
Additionally, Gluster with sharding is absolutely suggested for VM images. Sharding is developed exactly for VM images, as it decrease the healing time a lot and avoid full image locking.
from here: https://pve.proxmox.com/wiki/Storage:_GlusterFS ?After a node/brick crash, GlusterFS does a full rsync to make sure data is consistent. This can take a very long time with large files, so this backend is not suitable to store large VM images.
that's absolutely wrong. Gluster doesn't need to do a full sync (and also it doesn't use rsync at all except for geo-replication) after a brick failure. Only missing files from that bricks are synced back, like in every other replicated system. Even in a RAID, if you loose a disk, you have to sync the whole disk.
Additionally, Gluster with sharding is absolutely suggested for VM images. Sharding is developed exactly for VM images, as it decrease the healing time a lot and avoid full image locking.