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tanislavm's avatar
tanislavm
Level 6
11 years ago
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config

Hi, If I run in jeopardy case and I have only one private NIC link between 2 nodes vcs in production,what should I perform first?I mean it is enough to add heartbeat traffic over public area between the 2 nodes by editing llttab file,or I should also add 2 LUNs as hearbeatdisks maybe at 100 mb.Is this size fine? So I stop vcs with aplications running,and I unload gab and llt modules on both nodes,then with llttab modified on both nodes I start vcs.right? Is this enough?Or also some disk fencing will be recommended but not compulsory. thanks so much.
business continuity
Solaris
Storage Foundation
  • Gaurav_S's avatar
    Gaurav_S
    11 years ago
    Hi, It is always recommended to have 2 heartbeats with a low priority link. If in case 1 of heartbeat fail, you still have got 1 high priority link and 1 low priority link working, best wild be to focus and get second high priority link working again. Also fencing is recommended always to protect from split brain Disk heartbeat I have came across in near past of someone using it G

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  • mikebounds's avatar
    mikebounds
    Level 6
    11 years ago

    If you get jeopardy, you could add a lowpri link to llttab which would require stopping and starting llt - there is no need to unload kernel module, just stop using lltconifg -U and start using lltconfig -c (as gab depends on llt and VCS depends on gab, you will need to restart gab and VCS also and you can use "hastart -all -force" to stop VCS so apps remain running).

    However, it is better to setup low-pri link before you have an issue, which will only be used for infrequent heartbeats when both private heartbeats are working and will be promoted to full heartbeat if it is the only heartbeat left.

    Fencing is recommended by Symantec, but not compulsory and in practice most customers only use fencing where it is mandatory for SFCFS, because although fencing is good in theory, it can bring down nodes when you don't want it to because of admin error, bugs, or just certain side case scenarios.

    Mike

  • Gaurav_S's avatar
    Gaurav_S
    Moderator
    11 years ago
    Hi, It is always recommended to have 2 heartbeats with a low priority link. If in case 1 of heartbeat fail, you still have got 1 high priority link and 1 low priority link working, best wild be to focus and get second high priority link working again. Also fencing is recommended always to protect from split brain Disk heartbeat I have came across in near past of someone using it G