Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hello, I am currently planning a migration of a one-machine setups to a two-machine-cluster. Part of it will be migrating existing data to DRBD, and I hope you can help me with this. The current storage layout looks like this: ext4 -> LVM -> LUKS/dm_crypt -> mdadm raid -> sda2/sdb2 That is, we have a software raid (level 5), which is encrypted using LUKS. The encrypted device is PV for the LVM, which has one VG and multiple ext4 formatted LVs. I'd like to add DRBD like this: ext4 -> LVM -> LUKS/dm_crypt -> DRBD -> mdadm raid -> sda2/sdb2 My primary goal is to let only one machine do the encryption (which will be a new machine with AESNI) and then have DRDB distribute that encrypted data to two machines. Is this possible, and how would I go about migrating the existing setup without losing any data? As I understand it, you would have to create a DRBD device with /dev/md0 as lower-level device on each machine. Then you would have to change the LUKS setup to open /dev/drbd0 as encrypted device; from then on the LVM layer should see no difference, since it is still using /dev/mapper/<crypted_volume> as PV, right? What about metadata in this setup? Where would/could DRBD store it in this case? Do some of DRBDs features like checksum-based replication make sense in such a setup? Thanks for your help, Andreas