Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi, I am observing a quite strage behaviour: The generation identifier UUIDs on my nodes differ although the volumes are connected and reported in-sync (in fact they are really in-sync, I ran a verify). Regarding to https://drbd.linbit.com/users-guide/s-gi.html this should not happen. I find it quite odd that the differences in UUID was always only 1 so far: Here GIs from node A: [root at nodea:~]# drbdadm get-gi all 749E0550B4C8120C:0000000000000000:B36328481DC19155:B36228481DC19155:1:1:0:1:0:0:0 CA23BF5B6198E2A2:0000000000000000:37EC37F7420D2057:37EB37F7420D2057:1:1:0:1:0:0:0 AD2A6DB42BD2E1E6:0000000000000000:8FF18D07624D26DA:8FF08D07624D26DA:1:1:0:1:0:0:0 [root at nodeb:~]# drbdadm get-gi all 749E0550B4C8120C:0000000000000000:B36328481DC19154:B36228481DC19155:1:1:0:1:0:0:0 CA23BF5B6198E2A2:0000000000000000:37EC37F7420D2056:37EB37F7420D2057:1:1:0:1:0:0:0 AD2A6DB42BD2E1E7:0000000000000000:8FF18D07624D26DA:8FF08D07624D26DA:1:1:1:1:0:0:0 Here for the 3rd volume, the currend GI UUID differs by 1. For the 1st and 2nd volume, the younger history GI UUID differs by 1. Is this in any way an expected behaviour? I think that I hit a bug -- might it cause further problems? I see no warnings about UUIDs not matching in the kernel log. The only problem I see is that the replication link seems to have disconnected for two seconds right after boot. This seems to happen due to reconfiguration of bonding. After that DRBD started to sync and completed successfully, but here the UUID was updated to the not-matching number: Node A: ... [ 32.358379] block drbd10100: drbd_sync_handshake: [ 32.358383] block drbd10100: self 8FF08D07624D26DA:0000000000000000:34233B59A66A8C62:34223B59A66A8C63 bits:0 flags:0 [ 32.358385] block drbd10100: peer AD2A6DB42BD2E1E7:8FF08D07624D26DA:34233B59A66A8C63:34223B59A66A8C63 bits:0 flags:0 see here -------------------------------------------^ [ 32.358387] block drbd10100: uuid_compare()=-1 by rule 50 ... [ 32.372810] block drbd10100: Began resync as SyncTarget (will sync 0 KB [0 bits set]). [ 32.373783] block drbd10100: Resync done (total 1 sec; paused 0 sec; 0 K/sec) [ 32.373787] block drbd10100: updated UUIDs AD2A6DB42BD2E1E6:0000000000000000:8FF18D07624D26DA:8FF08D07624D26DA see here ----------------------------------------------------^ [ 32.373790] block drbd10100: conn( SyncTarget -> Connected ) disk( Inconsistent -> UpToDate ) ... Node B: ... [ 32.502916] block drbd10100: drbd_sync_handshake: [ 32.502924] block drbd10100: self AD2A6DB42BD2E1E7:8FF08D07624D26DA:34233B59A66A8C63:34223B59A66A8C63 bits:0 flags:0 see here -------------------------------------------^ [ 32.502929] block drbd10100: peer 8FF08D07624D26DA:0000000000000000:34233B59A66A8C62:34223B59A66A8C63 bits:0 flags:0 [ 32.502933] block drbd10100: uuid_compare()=1 by rule 70 ... [ 32.506619] block drbd10100: Began resync as SyncSource (will sync 0 KB [0 bits set]). [ 32.506645] block drbd10100: updated sync UUID AD2A6DB42BD2E1E7:8FF18D07624D26DA:8FF08D07624D26DA:34233B59A66A8C63 [ 32.512254] block drbd10100: Resync done (total 1 sec; paused 0 sec; 0 K/sec) [ 32.512262] block drbd10100: updated UUIDs AD2A6DB42BD2E1E7:0000000000000000:8FF18D07624D26DA:8FF08D07624D26DA see here ----------------------------------------------------^ [ 32.512272] block drbd10100: conn( SyncSource -> Connected ) pdsk( Inconsistent -> UpToDate ) ... System is CentOS 7.1, fully updated. drbd kernel module is version 8.4.6 from official tarball. drbd-utils is version 8.9.3 from official tarball. Both downloaded form http://oss.linbit.com/drbd/. Regards, // Veit