[mythtv-users] Disk space is not freed from deleted recording until mythbackend exits

[Michael T. Dean]

On 08/17/2006 08:54 PM, Jim O'Neill wrote:
> Michael T. Dean wrote:
>   
>> On 08/15/2006 10:06 PM, Jim O'Neill wrote:
>>> I've been having a problem for about two to three weeks now where the 
>>> space from a recording manually deleted from within mythfrontend is not 
>>> returned to the system until i exit mythbackend.
>> In SVN trunk, due to the new feature that performs deletes in chunks (to 
>> prevent I/O starvation), you won't see the disk space show up for quite 
>> some time--unless you stop mythbackend (which, BTW, should result in a 
>> flurry of I/O activity as the delete is completed in one chunk on 
>> killing mythbackend).  So, if you're using SVN trunk, delete a video and 
>> check your disk space in a few hours
> Mike, i think you may be right.
With the number of posts I make, it had to happen eventually.  ;)

> I am running SVN trunk and was aware of 
> this new method for deleting files but i wasn't aware that it is as slow 
> as it is and therefore thought that space wasn't being returned. 
>
> I just created a script to execute df every 60 seconds and ran this for 
> about 20 minutes between recordings.  I'm seeing 500 KB +/- a few bytes 
> being deleted every minute.  If my math is correct this works out to 16 
> hours to completely delete a 500 MB recording.  For the test i deleted 
> about 4 GB of recording which represents over 5 days before space is 
> returned. Does this sound right or do i have a problem somewhere else?

I've been on the road for 3 weeks.  I take TV recordings on my laptop 
and delete all the shows I've watched that week all at once.  For 
example, last week I deleted 20GiB all at once, and I saw it show up in 
a couple of hours.

Warning:  The following is an observation that is /not/ based on 
interpretation of code.  I have not even looked at the code, so I may be 
way off.

While my system was recording shows, it seemed to use a very small chunk 
size (it was actually recording at my extremely-low bitrate (1.15GiB/hr) 
faster than deleting).  Once the recording ended, delete speed increased 
dramatically.

Mike

(Amazed at the number of people complaining about this feature having 
never used/seen it themselves, but basing their complaints on your 
/question/ about how slowly it deletes.)