[CentOS] lvm 1 drive fails whole vol data lost

Sun Dec 26 16:39:18 UTC 2010
William Warren <hescominsoon at emmanuelcomputerconsulting.com>

On 12/26/2010 11:04 AM, Kwan Lowe wrote:
> On Sat, Dec 25, 2010 at 2:23 PM, Ryan Wagoner<rswagoner at gmail.com>  wrote:
>> RAID 5 does provide speed increases for read operations. There are
>> still some applications where RAID 5 has its benefits. For a smaller
>> department file server 3-4 TB drives in RAID 5 works great. The money
>> saved can be put towards backups, etc. Having said that I use RAID 10
>> for most applications.
> I've been thinking about the whole backup/redundancy approach to
> maintaining my home network. Though it is a "home" network, I use it
> to support  my work so though it's not business critical, it can't
> tolerate much downtime.
>
> Two approaches that I see:
>
> 1) Use some form of RAID or mirroring and a backup process to provide
> recoverability.
>
> 2) Maintain a centralized configuration in order to quickly re-build a
> downed system.
>
> They  are not completely separate, but I've been trying to move my
> recovery philosophy to the latter to minimize costs.
>
> For example, I used to backup my DNS/LDAP server by creating a
> snapshot of the Xen LVM partition. Recovery was simply a matter of
> restoring the backup.
>
> The problem with this approach was that the number of virtual machines
> started to balloon and with it, the storage requirements.  Though the
> images were only 10G to 20G, I had dozens of them.  Not to mention
> that the virtualization hosts keep changing: VMWare Server stopped
> being free; The upstream vendor moved to KVM instead of Xen.
>
> The approach I'm taking now is to use a combination of
> Kickstart/Anaconda and cfengine with the goal of removing all host
> identity from a OS instance.
>
> For my DNS server, for example, I use kickstart to build a standard
> image with a cfengine client. On bootup, cfengine pulls in the bind
> configuration and within a few minutes I have a duplicate of the old
> server. This is also much more resilient to changes in the underlying
> VM technology.
>
> There are still some kinks to work out. For one, I haven't backed up
> the cfengine server the same way. Supposedly it's just a matter of
> making the server its own client, but right now I'm using an image
> backup and rsync copies to another fileserver.
>
> I'm also trying to integrate a Spacewalk server into the mix.  This
> will allow me to rebuild a system with the exact same packages (right
> now I just update to the latest). In a real production environment
> this is critical as some applications may only be certified against
> particular kernel/glibc/etc.  versions.
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vmware esxi is still free and it's superior to vmware server.  I don't 
know if you have the cpu to directly support the bare-metal hypervisor 
though.