[Gluster-devel] about Qluster FS configuration

[Felix Chu]

Hi Krishna, 

Thanks your quick reply. 

About self heal, is that mean before the event open() triggered, the whole
replication cluster will have one less replica than normal state? If our
goal is to make the replication status back to normal(same #of replicas as
normal), we need to trigger open() for all files store in the cluster file
system, right? If so, the easiest way is to "touch *" in the clustered mount
point, right?

By the way, we will setup a testing environment to create a GlusterFS across
20 data centres, each data centre has point to point fiber in between. The
longest distance between two data centres is about 1000km. Do you think
GlusterFS can be applied in this kind of environment? Any minimum network
quality between storage servers and clients?

Regards,
Felix

-----Original Message-----
From: krishna.zresearch at gmail.com [mailto:krishna.zresearch at gmail.com] On
Behalf Of Krishna Srinivas
Sent: Friday, November 16, 2007 4:19 PM
To: Felix Chu
Cc: gluster-devel at nongnu.org
Subject: Re: [Gluster-devel] about Qluster FS configuration

On Nov 16, 2007 1:18 PM, Felix Chu <felixchu at powerallnetworks.com> wrote:
> Hi all,
>
>
>
> I am new user to this QlusterFS project. I just started the test in local
> environment with 3 server nodes and 2 client nodes.
>
>
>
> So far, it works fine and now I have two questions:
>
>
>
> 1.      I cannot understand the option related to "namespace" clearly. I
> find that in most of the server conf files separated "DS" and "NS"
volumes,
> what is the purpose of it?
>

namespace is used :
* to assign inode numbers
* to readdir(), instead of reading contents of all the subvols, unify
readdir()s just from NS.

>
>
> e.g. in
>
http://www.gluster.org/docs/index.php/GlusterFS_High_Availability_Storage_wi
> th_GlusterFS
>
>
>
> there are "ds" and "ns" volumes in this config
>
> volume mailspool-ds
>
>            type storage/posix
>
>            option directory /home/export/mailspool
>
>    end-volume
>
>
>
>    volume mailspool-ns
>
>            type storage/posix
>
>            option directory /home/export/mailspool-ns
>
>    end-volume
>
>
>
> 2.      In my testing environment, I applied the replication function to
> replicate from one server to other 2 servers. Then I unplug one of the
> server. On client side it still ok to access the mount point. After a
> period, I up the unplugged server again and find that all data during the
> outage period does not appear on this server. Any steps required to sync
> data back to new recovered server?
>

You need to open() that file to trigger selfheal for that file.

Krishna