[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
...and...
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:
http://marc.info/?l=linux-ext4&m=125834107118172&w=2
...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.
Tom
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