[mythtv-users] Storage best practices in 2017

[Hika van den Hoven]

Hoi Mark,

Wednesday, March 22, 2017, 5:50:45 PM, you wrote:

> I'm getting ready to rebuild my main backend system, which has
> served me faithfully for the last 5 years with near no downtime,
> functioning as a mythtv backend, NAS server, zoneminder, asterisk
> and a couple other functions.  I do all this to keep powered
> computers to a minimum and save a bit on power costs. 


> The storage as it is now consists of 4 1TB western digital drives
> in Raid 5 with LVM on top for mythtv storage of recordings and
> video/ripped dvds.  I also have 2 1TB drives in Raid 1 for critical
> stuff i don't want to lose and don't need the striping for performance.


> I've decided the Raid 5 / LVM setup is too complex for what it is,
> and storage groups didn't exist when i originally built this rig.  


> I just picked up 2 4TB WDRed drives on the newegg hump day sale.  


> Looking for suggestions on where to go from here, with the
> following assumptions:  Video recordings/dvd rips i want to have
> some sort of protection from a drive fail.  Recordings i don't care as much.


> What's the current thought on best practices for storage?  I had
> looked at ZFS for preventing bit-rot.  Not opposed to Raid still,
> but probably not that interested in the LVM combo anymore.


> Any thoughts?
> Sent from my T-Mobile 4G LTE Device 


I have been using for over 10 years with much satisfaction lvm on
raid1. What filesystem you want to put on your volumes is another
discussion that also depends on the use. raid1 is simpler and faster
then raid5, but uses double the diskspace of what you have in the end.
The advantage of lvm is that you at the start never know what you're
going to need, but now you can adjust at need. Couple the two disks in
raid1 without any partitioning. Make it a PV. put a VG on it and
make the LVs you are going to need. You can leave space in the VG
unused for later allocation, move space from one LV to another, add a
new raid1 couple to the VG, etc. You can even later add a 8Tb raid1
set, add it to the VG, move the data to the new PV and remove the old
raid1 array. And this all while the machine keeps doing its normal
tasks most of the time. Most will be managed in the background and the
system in essence won't see the difference. Only that suddenly more
space is available.

Another thing is; use another small and fast raid1 set for your
system. I have two 120 Gb kingston ssd disks. My root, boot and swap
are on a normal partitions, but parts (var, usr, opt, tmp, home) that
could later need extra space or could lock up the machine by
uncontrolled growth are on LVs. This is also a different VG. For
changes to these LVs you will need to boot from either a CD/DVD or a
different partition. For that I have a small minimal installation on a
separate partition. 

It makes your system flexible.

Tot mails,
  Hika                            mailto:hikavdh at gmail.com

"Zonder hoop kun je niet leven
Zonder leven is er geen hoop
Het eeuwige dilemma
Zeker als je hoop moet vernietigen om te kunnen overleven!"

De lerende Mens