# Hast



## bluetick (Sep 30, 2011)

Anyone using HAST? Likes and dislikes? Limitations you have found? Can you rebuild the data from one disk to another after a drive failure? (as the wiki states some modes are still in the works)

Looks like a straight forward setup.


http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/disks-hast.html
http://wiki.freebsd.org/HAST


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## Sylhouette (Oct 6, 2011)

I only use it in a test setup with ZFS on top, and everything seems ok.
Changed disks and so on.

The only thing i came across is the split brain issue.
In my case i use it with carp.
And it would be nice if you could check the state of the remote machine.
Something like hastctl --remote status, this way i can check the status of the remote machine, if that is still primary, you can script to wait to become primary itself.

Now (as far as i know) i can not do that, so i got the split brain a few times.

regards,
Johan Hendriks


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## jake (Oct 10, 2011)

Have you tried net-mgmt/hastmon from the ports instead of using carp, it adds a watchdog server into the mix, this quote from the README explains more



> HASTMON is designed for clusters that work in Primary-Secondary configuration, which means that only one of the cluster nodes can be active at any given time. Active node will be called Primary node. This is the node that will run the service. Other nodes will be running as Secondary ensuring that the service is not started there. There should be also at least one node acting as a watchdog -- it checks periodically status of all nodes and sends complaints to Secondary nodes if Primary is not available. Secondary node makes decision to change its role to Primary when two conditions are meat: there is no connection from primary and there are complaints from watchdog.



I have been testing hastmon for a week or so, it's pretty cool. The cli and configuration is very much like hast's so it's very easy to get acquainted with it. 

I believe you can have more than one watchdog server, if you worried about the watchdogs redundancy.


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