anyone ? On Fri, Mar 17, 2017 at 5:40 PM, Alejandro Comisario <alejandro@xxxxxxxxxxx> wrote: > Hi, it's been a while since im using Ceph, and still im a little > ashamed that when certain situation happens, i dont have the knowledge > to explain or plan things. > > Basically what i dont know is, and i will do an exercise. > > EXCERCISE: > a virtual machine running on KVM has an extra block device where the > datafiles of a database runs (this block device is exposed to the vm > using libvirt) > > facts. > * the db writes to disk in 8K blocks > * the connection between the phisical compute node and Ceph has an MTU of 1500 > * the QEMU RBD driver uses a stipe unit of 2048 kB and a stripe count of 4. > * everything else is default > > So conceptually, if someone can explain me, what happens from the > momment the DB contained on the VM commits to disk a query of > 20MBytes, what happens on the compute node, what happens on the > client's file striping, what happens on the network (regarding > packages, if other than creating 1500 bytes packages), what happens > with rados objects, block sizes, etc. > > I would love to read this from the bests, mainly because as i said i > dont understand all the workflow of blocks, objects, etc. > > thanks to everyone ! > > -- > Alejandrito -- Alejandro Comisario CTO | NUBELIU E-mail: alejandro@nubeliu.comCell: +54 9 11 3770 1857 _ www.nubeliu.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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