[Linux-cluster] Re: If I have 5 GNBD server?

[brianu]

Hello all,

 

This is a question I have basically been asking, the question on why you
would want to do it is failover, the docs at
http://sourceware.org/cluster/gnbd/gnbd_usage.txt state that dm-multipath is
an option for gnbd, and documents elsewhere also indicate that GNBD can be
configured as a redundancy, yet I cannot find any documentation on how to
configure it.

 

If using LVM to make a volume of imported gnbds is not the answer for
redundancy can anyone suggest a method that is? Im not opposed to using any
other resource of cluster or GFS but I would really like to implement a
redundant solution, ( gnbd, gulm, etc.).

 

 

Does anyone has an example of a redundant solution for a cluster/gfs
filesystem i.e ( gnbd, gulm etc) ?

 

Regards,

 

Brian

 

Message: 9

Date: Fri, 26 Aug 2005 16:33:51 +0700

From: "Fajar A. Nugraha" <fajar at telkom.co.id>

Subject: Re: [Linux-cluster] Re: If I have 5 GNBD server?

To: linux clustering <linux-cluster at redhat.com>

Message-ID: <430EE1FF.6050505 at telkom.co.id>

Content-Type: text/plain; charset=ISO-8859-1; format=flowed

 

Michael wrote:

 

>Can anyone answer my question?

> 

>  

> 

I don't think LVM cares what kind of storage it uses, as long as it's a 

block device.

So theoretically, you can mix local disc, FC storage, GNBD, and ATOE and 

combine them using LVM. You might run into performance issues (GNBD are 

slower than FC disks) and startup issues (LVM has to start after cluster 

and gnbd-import successfuly start), but it should be possible.

 

The real question is WHY you want to do that.

AFAIK, if you combine 5 gnbd from 5 gnbd servers into one LVM, and you 

are accessing a volume on that volume group, and one of the gnbd server 

dies (or hangs), gnbd import will wait forever until that server is back 

up. So you'll have five more single-point-of-failures.

 

Regards,

 

Fajar

 

>On 8/26/05, Michael <mikore.li at gmail.com> wrote:

>  

> 

>>Hi,

>> 

>>If I have 5 gnbd servers in the network, each one export 1 block

>>device, can I import all gnbd devices on each gfs client, and use lvm

>>to manage them as 1 shared pool, then mkfs_gfs on it?

>> 

>>Thanks,

>> 

>>Michael

>> 

>>    

>> 

> 

>  

> 

 

 

 

Brian Urrutia

System Administrator

Price Communications Inc.

 

There are 10 types of people in this world, 
those who understand binary and those who don't.

 

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