[CentOS] CentOS MD RAID 1 on Openfiler iSCSI

Mon Jun 28 20:25:44 UTC 2010
Emmanuel Noobadmin <centos.admin at gmail.com>

On 6/29/10, Karanbir Singh <mail-lists at karan.org> wrote:
> On 28/06/2010 20:31, Emmanuel Noobadmin wrote:
>> I haven't tried it yet, still researching on which way to go (looked
>> into Lustre, then glusterFS, then now this). Coincidentally, I just
>
> Not sure what you are trying to do here. Lustre, glusterfs, gfs etc
> solve a different problem than imported remote storage ( which is
> essentially what iscsi will give you )

As my username suggests, I don't know what I'm doing. Server
admin/setup is secondary to my primary job of writing web-based
applications.

I'm trying to figure out a setup that would allow me to add VM guests
on more than two VM server and provide data redundancy to these
without having to add physical machines unnecessarily.

With just two machines, I could simply mirror them. But if I have more
VM guest than they can comfortably handle (or more than I am
comfortable), 3 servers seem a bit more tricky. Also if I need more
storage capacity than processing power, which is more usually the case
due to backup and history data, each physical server has a limit.

So I figured I might as well try to find a singular setup (less
administrative headache for the amateur admin) with a VM/data cluster
that can survive a single drive failure per machine as well as single
machine failure. I would then use this setup for the current client's
demand to try things out before the next one which will really need
the flexibility and redundancy.


> I dont see why not. But you dont dont need openfilter to give you iscsi
> capability. CentOS-5.1+ has had the ability to export an iscsi target
> itself with all the tooling built in.

I'm not sure yet since openFiler seems to provide a few more options,
if I'm not mistaken the ability to soft RAID 5/6 on multiple machines
and remote block duplication. So theoretically, I'm thinking with
openFiler presenting a frontend to the application servers, I could
increase storage without having to mess with the application server
setup.

i.e. they still see a pair of iSCSI from the openFiler servers, which
then RAID 5/6 iSCSI servers (physical or VM initially) to provide the
storage and can be increased at any time transparent to the
application servers.