[mythtv-users] SMR drives on Mythtv

[Stephen Worthington]

On Tue, 30 Jan 2018 22:32:17 -0500, you wrote:

>Does anyone have an opinion on SMR type drives for PVR applications such 
>as myth?  Newegg has a really good deal on 4TB Seagate SMR drives for 
>$89 right now.

As far as I know, the smallest shingled drive that Seagate makes is 8
Tbytes.  Do you have a URL for the Newegg ones?  It is likely that
Newegg is mislabeling them as SMR when they are actually normal
drives.  You need to look up the model number on Seagate's web site
and download its data sheet to find out.

Shingled drives are unsuitable for recording to, as when they have to
do a shingle re-write, they can stop accepting write data for a long
period - many seconds.  The MythTV recording buffers and operating
system write buffers are nowhere near big enough to buffer that much
data and will overflow, resulting in lost data in the middle of the
recording.

However, you can use SMR drives as storage for recordings - I have
four Seagate ST8000AS0002 (8 Tbyte) drives that I use that way.
Recordings go to my seven non-shingled recording drives, and the
recording files can be copied off to the SMR drives once recording is
completed.  I wrote myself some Python to automate the process of
selecting the oldest recordings and moving them to the SMR drives,
which I have in an "archive" storagegroup so that MythTV can see all
the recording files.  But as I do not have any recording rules that
will record to the archive storagegroup, those drive are never used
for recording to.