[CentOS] Looking for a life-save LVM Guru

[Valeri Galtsev]

On Fri, February 27, 2015 10:00 pm, Marko Vojinovic wrote:
> On Fri, 27 Feb 2015 19:24:57 -0800
> John R Pierce <pierce at hogranch.com> wrote:
>> On 2/27/2015 4:52 PM, Khemara Lyn wrote:
>> >
>> > What is the right way to recover the remaining PVs left?
>>
>> take a filing cabinet packed full of 10s of 1000s of files of 100s of
>> pages each,   with the index cards interleaved in the files, and
>> remove 1/4th of the pages in the folders, including some of the
>> indexes... and toss everything else on the floor...    this is what
>> you have.   3 out of 4 pages, semi-randomly with no idea whats what.
>
> And this is why I don't like LVM to begin with. If one of the drives
> dies, you're screwed not only for the data on that drive, but even for
> data on remaining healthy drives.
>
> I never really saw the point of LVM. Storing data on plain physical
> partitions, having an intelligent directory structure and a few wise
> well-placed symlinks across the drives can go a long way in having
> flexible storage, which is way more robust than LVM. With today's huge
> drive capacities, I really see no reason to adjust the sizes of
> partitions on-the-fly, and putting several TB of data in a single
> directory is just Bad Design to begin with.
>
> That said, if you have a multi-TB amount of critical data while not
> having at least a simple RAID-1 backup, you are already standing in a
> big pile of sh*t just waiting to become obvious, regardless of LVM and
> stuff. Hardware fails, and storing data without a backup is just simply
> a disaster waiting to happen.
>

Indeed. That is why: no LVMs in my server room. Even no software RAID.
Software RAID relies on the system itself to fulfill its RAID function;
what if kernel panics before software RAID does its job? Hardware RAID
(for huge filesystems I can not afford to back up) is what only makes
sense for me. RAID controller has dedicated processors and dedicated
simple system which does one simple task: RAID.

Just my $0.02

Valeri

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Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
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