Dear Janne, I'm concerned with the potential increased NVME wear. Assuming writes of multiples of the block size, when I write 1GB of data to the CephFS, how much data is written to the disks? Best wishes, Manuel On Mon, Jan 30, 2023 at 2:25 PM Janne Johansson <icepic.dz@xxxxxxxxx> wrote: > > is there information available anywhere about the write amplification for > > CephFS? I found quite some material on write amplification of VMs using > > journaled file system on top of RBD but nothing as it relates to CephFS? > > > > From my understanding I would expect the following: > > > > - for X-rep, data needs to be written to X pgs (factor X) > > - for k-m EC, data is written to k+m pgs (factor (k+m)/k) > > > > Am I correct? > > Yes, but in the EC case, far smaller amounts of data will be sent to > each PG, so it depends on if you are calculating "amplification" in > terms of IOPS or in terms of MBytes (that needs to be sent over the > network and written to disk). > > -- > May the most significant bit of your life be positive. > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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