Yes, o2cb will reboot one or 2 nodes. Are you sure, that system wil recover in normal state after all this, including ocfs2 and DRDB?
Another problem is that, in case of network glitch, you wil have both, interconnection lost and heartbeat delay, on second node (or on all nodes). Are you sure, that o2cb will understand such situation correctly? I mean that using DRBD makes direct dependency between drdb device access time and o2cb interconnections time, so it put ocfs2 stack in untested and very unusual situation. I can bet, tht it wil end up in cluster failure with 90% probability (if cluster lost interconnection for relatively short time, say - 30 sconds with 12 secondr heartbeat timeout for example). If you read Oracle, they show that DRDB do not satisfy to requirements for RAC cluster derundancy (in some scenarios). OCFS2 is even wort because it will use o2cb heartbeat thru DBDB and have much shorter timeouts (some of which are not configurable in old versions at all). So. It should work in the lab, allow to test many things, but don't try to test interconnection failures on it. ----- Original Message ----- From: "Kilian CAVALOTTI" <[EMAIL PROTECTED]> To: "Alexei_Roudnev" <[EMAIL PROTECTED]> Cc: <[email protected]>; <[EMAIL PROTECTED]> Sent: Friday, August 18, 2006 2:28 AM Subject: Re: [Ocfs2-users] OCFS2 over DRBDv8 On Thursday 17 August 2006 23:12, Alexei_Roudnev wrote: > I advice against it. Even if it is possible, you definitkly will run > into DRBD/o2cb conflict in case of any network glitch, > and will have all your nodes self-fencing. I'm not sure to understand the reasons of the conflict. In case of network failure, DRBD goes split-brain, and interrupts its synchronization procedures until manual recovery. In the mean time, o2cb will have detected the problem and fenced both nodes. Each node will operate in disconnected mode, that's expected behaviour, but why would DRBD and o2cb conflict? May you please give more details? > In addition, DRDB is not fast > enough for OCFSv2 default settings. May I ask why? DRBD speed is all about the interconnect link, isn't it? And with a GbE link, which outperforms most of the not-so-new IDE/SATA controllers, I'd appreciate any insights about how DRBD could be not fast enough for OCFS2. > Through, it all may be very interesting to discover in the lab. That's actually the case, I'm not planning to base any real-world service on such an infrastructure for now. That's more of a playground, actually. :) -- Kilian CAVALOTTI Administrateur réseaux et systèmes UPMC / CNRS - LIP6 (C870) 8, rue du Capitaine Scott Tel. : 01 44 27 88 54 75015 Paris - France Fax. : 01 44 27 70 00 _______________________________________________ Ocfs2-users mailing list [email protected] http://oss.oracle.com/mailman/listinfo/ocfs2-users
