[CentOS] CentOS MD RAID 1 on Openfiler iSCSI

Mon Jun 28 20:36:42 UTC 2010
Karanbir Singh <mail-lists at karan.org>

On 28/06/2010 21:30, Emmanuel Noobadmin wrote:
> Part of my concern with such a setup is the whole data system goes
> down too if the storage box dies due to say blown PSU or motherboard
> problem. Doesn't it?

Depends on how you set it up, if you have 2 machines ( disk nodes ),
exporting iscsi. 1 machine ( data node ) doing the import and sets up a
raid1; you can afford to have one of those two machines down. You *cant*
afford to have the data-node down. Thats where the filesystem lives. You
can potentially have the same disks from the disk-nodes imported to a
standby data node using something like drbd over the mdraid setup.
Alternatively, you can look at using a clustered filesystem and have it
go X way. But then you may as well use something like gnbd with gfs2
instead(!).

Yes, lots of options and different ways of doing the same thing. So
start at the top, make a list of all the problems you are trying to
solve. then split that into 3 segments:
- Must have
- Good to have
- Dont really need

And then evaluate what solutions meet your requirements best.

- KB