[mythtv-users] Recordings stay in database and on disk for some time after delete?

Tom Dexter digitalaudiorock at gmail.com
Tue Mar 2 16:26:52 UTC 2010

On Thu, Feb 25, 2010 at 4:02 PM, Tom Dexter <digitalaudiorock at gmail.com> wrote:
> On Thu, Feb 25, 2010 at 3:52 PM, Vince Coen <vbcoen at btconnect.com> wrote:
>> On Thursday 25 Feb 2010, Tom Dexter wrote:
>>> On Sun, Feb 21, 2010 at 10:31 PM, Tom Dexter <digitalaudiorock at gmail.com>
>> wrote:
>>> Wow...I just deleted a bunch of shows (older episodes of The Dr. Oz
>>> Show) and the same thing is happening.  They disappear from the
>>> recorded programs when you delete them (in either the frontend or
>>> mythweb) but upon exiting and reentering the list they still show
>>> until the slow delete is actually finished.  I'm thinking about
>>> converting by recordings drive to ext4 and bagging the slow deletes
>>> once and for all, but I'd really like to know if this is how it works
>>> now.
>>> Am I the only one seeing this happen?
>> On my system I have configured the partition used to store recordings on to
>> XFS.
>> Deletes are very quick eg, seconds. Both ext3 & 4 are very slow to delete
>> which is why a setting is available to set this on to minimise cpu cycles.
>> Vince
> My understanding is that ext4 deletes large files very quickly.  As I
> noted previously however, this (I believe) would only apply to files
> actually created after an ext3 file system is converted to ext4, as
> the old files will not have extents.
> Tom

Just a follow up to this...

I just converted my recordings file system from ext3 to ext4 using:

tune2fs -O extents,uninit_bg,dir_index /dev/vg/video
fsck -f /dev/vg/video

...note that the Gentoo wiki had "fsck -fp /dev/vg/video" but in my
case I had to run it without the 'p' option and answer 'y' to a prompt
as there were invalid group descriptor checksums that needed to be
fixed...apparently this is expected:


...anyway...I can verify that after doing this, deleting existing
files created before the conversion (that don't use extents) is just
as slow as with ext3:

du 1071_20091126183000.mpg
2.6G 	1071_20091126183000.mpg
time rm -f 1071_20091126183000.mpg
real	0m6.873s
user	0m0.000s
sys	0m0.204s

...almost 7 seconds for a 2.6 GB file.  However a new file created with a copy:

cp 1581_20100228213000.mpg tom.mpg
du tom.mpg
8.7G 	tom.mpg
time rm -f tom.mpg
real	0m0.325s
user	0m0.000s
sys	0m0.304s

...instantaneous for all intents and purposes even for a nearly 9 GB file.

I guess I'll turn off slow deletes after the recordings made before
today work their way out of the system.


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