----- Original Message ----- > From: "Tony Hoyle" <t...@hoyle.me.uk> > To: "Gluster Users" <gluster-users@gluster.org> > Sent: Tuesday, May 1, 2018 5:38:38 AM > Subject: Re: [Gluster-users] Finding performance bottlenecks > > On 01/05/2018 02:27, Thing wrote: > > Hi, > > > > So is the KVM or Vmware as the host(s)? I basically have the same setup > > ie 3 x 1TB "raid1" nodes and VMs, but 1gb networking. I do notice with > > vmware using NFS disk was pretty slow (40% of a single disk) but this > > was over 1gb networking which was clearly saturating. Hence I am moving > > to KVM to use glusterfs hoping for better performance and bonding, it > > will be interesting to see which host type runs faster. > > 1gb will always be the bottleneck in that situation - that's going too > max out at the speed of a single disk or lower. You need at minimum to > bond interfaces and preferably go to 10gb to do that. > > Our NFS actually ends up faster than local disk because the read speed > of the raid is faster than the read speed of the local disk. > > > Which operating system is gluster on? > > Debian Linux. Supermicro motherboards, 24 core i7 with 128GB of RAM on > the VM hosts. > > > Did you do iperf between all nodes? > > Yes, around 9.7Gb/s > > It doesn't appear to be raw read speed but iowait. Under nfs load with > multiple VMs I get an iowait of around 0.3%. Under gluster, never less > than 10% and glusterfsd is often the top of the CPU usage. This causes > a load average of ~12 compared to 3 over NFS, and absolutely kills VMs > esp. Windows ones - one machine I set booting and it was still booting > 30 minutes later!
Are you properly aligned? This sounds like the xattr reads / writes used by gluster may be eating you IOPs, this is exacerbated when storage is misaligned. I suggest getting on the latest version of oVirt(I have seen this help) and evaluate your storage stack. https://access.redhat.com/documentation/en-us/red_hat_gluster_storage/3.1/html/administration_guide/formatting_and_mounting_bricks pvcreate --dataalign = full stripe(RAID stripe * # of data disks) vgcreate --extensize = full stripe lvcreate like normal mkfs.xfs -f -i size=512 -n size=8192 -d su=<stripe size>,sw=<number of data disks> DEVICE And mount with: /dev/rhs_vg/rhs_lv/mountpoint xfs rw,inode64,noatime,nouuid 1 2 I normally used tuned profile rhgs-random-io and the gluster v set group virtualization. HTH -b > > Tony > _______________________________________________ > Gluster-users mailing list > Gluster-users@gluster.org > http://lists.gluster.org/mailman/listinfo/gluster-users _______________________________________________ Gluster-users mailing list Gluster-users@gluster.org http://lists.gluster.org/mailman/listinfo/gluster-users
