[mythtv-users] Storage best practices in 2017

[Mark Wedel]

On 03/23/17 07:31 PM, Will Dormann wrote:
> On 3/22/17 12:50 PM, Mark wrote:
>> 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.
>
> That's a little confusing.  You care about "video recordings" but not
> "recordings" ?
>
>
>> 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.
>
>
> I'd only consider ZFS if you've got 8GB of RAM or more.  The more the
> merrier.
>
>
> Using ZFS (with more than one drive, obviously) or a RAID (linux md) can
> help minimize downtime in the case of a drive failure.   With or without
> redundant drives, you'll want two things to be safe:
> 1) Backups.    RAID isn't backup, yadda yadda...
> 2) Configure smartd to do scheduled self tests (I do daily short and
> weekly long) *and* configure it to email you in the case of a failing drive.
>
> At least with spinning-platter disks, properly-configured SMART will
> often give you a warning before the drive dies.  (it will die).  With
> SSDs, I'm not completely sure how useful SMART is.

  Having just had an SSD fail, not sure if SMART would have been useful.  In my 
particular case, this SSD failure isn't about write errors - it has just 
disappeared from the system.  I even power cycled the system and swapped the 
cables to it with those of it mirror, and still not there.

  So this is almost certainly a controller failure of the SSD (which can also 
happen to HDs), which SMART probably would not catch.

  Fortunately, this was part of my mirrored root disk, so no data loss (or even 
downtime, other than my fiddling trying to get it work) was encountered.

  As far as backups, always useful, but if you are using ZFS, look into 
snapshots.  I do nightly snapshots on my home directory (which is mirrored). 
This won't cover the case of computer catching on fire (in which case you need 
backups), but I find the vast majority of data loss to be accidental 
overwrite/deletion of files, and snapshots do cover you for that (you can also 
use the snapshots via zfs send to make your backups)