[mythtv-users] Storage group Question for Mike Dean..

[Michael T. Dean]

On 01/15/2013 10:01 AM, Greg wrote:
> On 01/15/2013 12:43 AM, Michael T. Dean wrote:
>> On 01/14/2013 04:12 PM, Greg wrote:
>>>  Mike, or any one else who can shed some light on this...
>>>    I have under the Default storage Group the paths to the disks I use
>>> to store recordings.
>>> /video2/storage/recordings/
>>> /video3/storage/recordings/
>>> /video6/storage/recordings/
>>>
>>> video2-6 are separate drives.. The permissions are set to read and
>>> write for the user that runs Mythtv... The only drive that is getting
>>> recorded to is /video6/storage/recordings/... This used to work for
>>> me,but after reading the current thread on storage groups,I noticed
>>> all but one storage group is empty...
>>>
>>> Would you be able to steer me in the right direction?
>>
>> First, according to the above, you've mentioned only one Storage Group,
>> called Default.  /video{2,3,6}/storage/recordings are directories, not
>> Storage Groups.  (Just making sure we're clear on terminology.)
>>
>> So, your Storage Group is not empty.  You may have 2 empty
>> directories--which is perfectly reasonable, and may be exactly what
>> you're telling MythTV to do.  To find out, we'd need more information.
>> Specifically, I'd need information about the file systems, such as the
>> output of df -k
>>
>> If, for example, /video2 is a file system on a 2TB HDD and /video3 and
>> /video6 are smaller file systems (say, on 500GB HDDs), and you have more
>> space available on /video2 than is available on either of the smaller
>> file systems, MythTV would choose to write to the /video2 file system
>> with the Balanced Free Space Storage Group Disk Scheduler.
>>
>> You should also check permissions, as Thomas mentioned, but
>> specifically, you'd need to check permissions of the directories leading
>> up to the final.  If MythTV doesn't have access to one of the
>> lower-level directories, it may not be able to see the recordings
>> subdirectory, so it won't use it.  If, however, the permissions were
>> correct, except for the recordings subdirectory, MythTV would attempt to
>> use it, then you'd get failures when trying to write the recordings, so
>> you'd have "missing" recordings.  So, check:
>>
>> ls -ld /video{2,3,6}{,/storage{,/recordings}}
>>
> First thanks for your time: I think my confusion is in thinking that 
> all recording storage groups were supposed to be under Default...

A Storage Group is a list of directories to which MythTV can write.  So, 
for example, "Default" is a Storage Group and on your setup it has 3 
directories (or paths) in the Storage Group.  I was just trying to 
emphasize the difference between "Storage Group" (list of directories) 
and "directory" (an actual location on the file system).

> Here is the info you requested..
> Filesystem      1K-blocks      Used Available Use% Mounted on
> /dev/sda7        57666820  38760492  15977024  71% /
> udev              2014960         4   2014956   1% /dev
> tmpfs              809664      2324    807340   1% /run
> none                 5120         0      5120   0% /run/lock
> none              2024152       172   2023980   1% /run/shm
> none               102400        68    102332   1% /run/user
> /dev/sda5        94050224   4027676  85245076   5% /video5
> /dev/sda1          140805    105494     28041  80% /boot
> /dev/sdd1      1442145340 978161808 390726728  72% /video1
> /dev/sdc1       961432072 667801396 244792676  74% /video2
> /dev/sde1       961431880 636842280 275751612  70% /video3
> /dev/sdb1       961431880 191096156 721497736  21% /video4
> /dev/sdf1      1922859824 953418304 871765848  53% /video6
> /dev/sr1         48876416  48876416         0 100% /media/greg/PIRATES1
> /dev/sr0          7052386   7052386         0 100% 
> /media/greg/CSI_MIAMI_S9_D4
> greg at TVserver:~$
> drwxrwxrwx  8 greg greg    4096 Jan 14 16:42 /video2
> drwxrwxrwx  3 greg mythtv  4096 Jun  3  2012 /video2/storage
> drwxrwxrwx  2 greg mythtv  4096 Jan 14 16:42 /video2/storage/recordings
> drwxrwxrwx  8 greg greg    4096 Nov  8 19:39 /video3
> drwxrwxrwx  3 greg mythtv  4096 Nov  8 19:40 /video3/storage
> drwxrwxrwx  2 greg mythtv 20480 Jan 14 15:52 /video3/storage/recordings
> drwxrwxrwx 13 greg greg    4096 Jan 14 15:09 /video6
> drwxrwxrwx  3 greg mythtv  4096 Mar 18  2012 /video6/storage
> drwxrwxrwx  2 greg mythtv 32768 Jan 15 00:56 /vi
>
>  As you can see I elevated all the permission to 777 trying to get 
> this to work...
> Do you see anything glaring that I missed?

It looks to me like MythTV is doing exactly as it should for a system 
configured to use the "Balanced free space" Storage Group Disk Scheduler 
( http://www.mythtv.org/wiki/Storage_Groups#Storage_Group_Disk_Scheduler 
).  The file system mounted at /video6 has 871765848 kiB available and 
all other file systems have less space available.  So, as long as you're 
using "Balanced free space" (which I'm assuming you're using as it would 
perfectly explain the behavior you're seeing and it's the default) and 
as long as /video6 has more space than any other file system available 
via the Storage Group list of directories, MythTV will write only to the 
file system on /video6.

If you'd like to spread out the load better, use a different disk 
scheduler, like "Combination" (my favorite) or "Balanced disk I/O".  
Note, also, that when your file system(s) get full, you do not want to 
use "Balanced free space" (or "Balanced percent free space").

Sorry for taking so long to get back to you.  Busy...

Mike