[CentOS] lvm 1 drive fails whole vol data lost

Sat Dec 25 07:15:40 UTC 2010
Benjamin Smith <lists at benjamindsmith.com>

On Friday, December 24, 2010 06:40:06 am Ryan Wagoner wrote:
> LVM is just like the name implies a logical volume manager. It allows
> you to easily combine and carve space from physical disks. It doesn't
> provide any redundancy. If you want redundancy you either need to use
> the LVM mirror capability, linux software raid with mdadm, or a
> hardware raid card.

It's been said before, and never seems to be said often enough: backup your 

IMHO, very few people really need RAID. In many (most?) cases, the added 
complexity of RAID is as likely to cause an increase of failure rate similar 
to or greater than the reduction of failure rate caused by the resiliancy of 
hardware. RAID won't protect you if you issue a perfectly legitimate command 
to delete data that was made in error. I once thought I needed RAID, and since 
realized the error in my ways, finding that the cases where RAID helped (one!) 
was vastly outnumbered by the cases where it made no difference (10? 11?) or 
actually worked against me. (2) Now, I don't bother with RAID even though my 
needs have grown from one server to 16, instead providing redundancy at the 
machine level: if a server goes, another picks up the load, in most cases 
automatically, in near-real-time. I can do this because I host a custom-made 
application with these objectives carefully designed for. 

The MUST HAVE option: a backup! Backups provide real, multi-point redundancy, 
some protection against the "Ooops, I didn't mean to delete that file" 
scenario, etc. and are there when all else has failed. I'd happily point you 
to my set of scripts that coordinate disk-to-disk backups over a network with 
automatically expired snapshot points. 

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