[mythtv-users] rebalance deleted recordings

[Michael T. Dean]

On 03/20/2014 10:58 AM, Simon Hobson wrote:
> It is a known problem (in that it's come up here before) that Myth doesn't always "get it right" when disks are full/nearly full.

No, MythTV only has a problem when the user specifies the /wrong/ 
Storage Group Disk Scheduler ( 
http://www.mythtv.org/wiki/Storage_Groups#Storage_Group_Disk_Scheduler 
).  If you run MythTV with full disks, you should be fine as long as you 
don't specify "Balanced Free Space" or "Balanced Percent Free Space" 
disk schedulers.  (Note, too, that "Balanced Free Space" is the 
default--because users complained that it wasn't.  So, you need to 
change this if you plan to run with full disks.

> * Statistically, unless you do something odd, then the recordings you delete are going to be spread across the drives. One "odd" thing would be to fill a drive up with old recordings that you don't get round to watching and deleting, but add an extra drive - so you only watch and delete "new" recordings that went onto the new drive.

Note, too, that as long as you're not using the "Balanced Free Space" or 
"Balanced Percent Free Space" Storage Group Disk Schedulers, you'll get 
the same "statistical" balancing you see.

> To put some numbers on that, when I put a new drive in a few weeks ago, I had about 40-50G of free space on the (then) only 3TB drive. That drive still has 40-50G of space free on it, but the other drive (which I upgraded from a 750 to 3TB) has between 100 and 200G of extra recordings on it**. So Myth is automatically favouring the less full drive,

Because you told it to...

>   and my "watch and delete" process is keeping free space up on the fuller drive even though I'm adding to the total quantity of recordings.

But if you're generally watching only new stuff, then you're only 
watching from the new/empty/"most free space" drive, so are no longer 
balancing...

Mike