On 2/19/20 3:17 PM, Frank R wrote: > Hi all, > > I have noticed that RedHat is willing to support 2x replication with > NVME drives. Additionally, I have seen CERN presentation where they > use a 2x replication with NVME for a hyperconverged/HPC/CephFS > solution. > Don't do this if you care about your data. NVMe isn't anything better or worse than SSDs. It's actually still an SSD, but we swapped the SATA/SAS controller for NVMe, but it's still flash. > I would like to hear some opinions on whether this is really a good > idea for production. Is this setup (NVME/2x replication) really only > meant to be used for data that is backed up and/or can be lost without > causing a catastrophe. > Yes. You can still loose data due to a single drive failure or OSD crash. Let's say you have an OSD/host down for maintenance or due to a network outage. The OSD's device isn't lost, but it's unavailable. While that happens you loose another OSD, but this time you actually loose the device due to a failure. Now you've lost data. Although you *think* you still have another OSD which is in a healthy state. If you boot the OSD you'll find out it's outdated because writes happened to the OSD you just lost. Result = data loss 2x replication is a bad thing in production if you care about your data. Wido > Thanks, > Frank > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
 |