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From Casey Deccio <ca...@deccio.net>
Subject Re: Disk configuration in new cluster node
Date Mon, 17 Sep 2012 15:53:53 GMT
On Mon, Sep 17, 2012 at 1:19 AM, aaron morton <aaron@thelastpickle.com>wrote:

>  4 drives for data and 1 drive for commitlog,
>
> How are you configuring the drives ? It's normally best to present one big
> data volume, e.g. using raid 0, and put the commit log on say the system
> mirror.
>
>
Given the advice to use a single RAID 0 volume, I think that's what I'll
do.  By system mirror, you are referring to the volume on which the OS is
installed?  Should the volume with the commit log also have multiple disks
in a RAID 0 volume?  Alternatively, would a RAID 1 setup be reasonable for
the system volume/OS, so the system itself can be resilient to disk
failure, or would that kill commit performance?

Any preference to hardware RAID 0 vs. using something like mdadm?

A word of warning. If you put more than 300GB to 400GB per node you may end
> experience some issues such as repair, compaction or disaster recovery
> taking a long time. These are simply soft limits that provide a good rule
> of thumb for HDD based systems with 1 GigE networking.
>

Hmm.  My hope was to be able to run a minimal number of nodes and maximize
their capacity because it doesn't make sense in my case to build or
maintain a large cluster.  I wanted to run a two-node setup (RF=1, RCL=ONE,
WCL=ALL), each with several disks having large capacity, totaling 10 - 12
TB.  Is this (another) bad idea?

Casey

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