Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi, To follow up on myself, there is no need to failover. I just tested this with a demo setup and the attach command was enough to get everything back to normal again. Kind regards, Caspar Smit 2011/7/29 Digimer <linux at alteeve.com>: > On 07/29/2011 07:46 AM, Caspar Smit wrote: >> Hi all, >> >> My primary node suffered a raid (md) failure and the drbd state is now: >> >> cs:Connected ro:Primary/Secondary ds:Diskless/UpToDate C r---- >> ns:76247848 nr:316725148 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 >> ep:1 wo:b oos:0 >> >> So drbd is passing all IO to the second node. >> >> In the meantime I fixed the md and now i'm ready to attach the md again. >> >> But here's my question: >> >> Do i NEED a failover so the secondary node becomes primary/uptodate or >> can drbd handle the fact that when I attach the md again the primary >> becomes synctarget / inconsistent, will it stil pass all IO to the >> secondary node first until the primary is uptodate again? >> >> in short: >> >> Will "drbdadm attach <resource>" be sufficient to recover from >> Primary/Diskless or do I need to do a failover first? >> >> Met vriendelijke groet, > > Simply reconnecting should be fine. > > As I understand Protocol C, writes will go to both nodes, and reads will > come from the UpToDate node. The details are probably best answered by a > dev or Linbit person directly though, as I am somewhat guessing. I am > sure you don't need to fail-over though. > > You may *want* to fail over though, if you can do so without downtime > (ie: live-migrate a VM, is that is what is using the DRBD storage). The > reason being that if anything happens to the communication with the > secondary, the primary will drop to Secondary until it's local storage > is UpToDate. > > -- > Digimer > E-Mail: digimer at alteeve.com > Freenode handle: digimer > Papers and Projects: http://alteeve.com > Node Assassin: http://nodeassassin.org > "At what point did we forget that the Space Shuttle was, essentially, > a program that strapped human beings to an explosion and tried to stab > through the sky with fire and math?" >