[mythtv-users] An LVM'd drive died! What do I do...

[Michael T. Dean]

Andrew Close wrote:

>On 10/27/05, Brandon Beattie <brandon+myth at linuxis.us> wrote:
>  
>
>>On Thu, Oct 27, 2005 at 02:42:15PM -0500, Andrew Close wrote:
>>    
>>
>>>On 10/27/05, Brandon Beattie <brandon+myth at linuxis.us> wrote:
>>><snip/>
>>>      
>>>
>>>>Hopefully in the next few months myth will support storing to multiple
>>>>directories, which would remove the need for LVM or having to worry
>>>>about losing anything but what was on that drive.
>>>>        
>>>>
>>>excellent thread! :)  i had to come back to the above statement
>>>because i've seen it mentioned before and am just looking for a little
>>>clarity.
>>>
>>>storing to multiple directories - what is meant by that?
>>>do you want to store all your Lost episodes in /myth/tv/Lost, and all
>>>of your SG-1 episodes in /myth/tv/SG-1?  so you have subdirectories
>>>under /myth/tv.
>>>
>>>or do you mean breaking outthe directories into their own partitions -
>>>/dev/hdb1 = /myth/tv/Lost
>>>/dev/hdb2 = /myth/tv/SG-1
>>>
>>>you can kind of do this now, can't you?  without the subdirectories -
>>>/dev/hdb1 = /myth/tv
>>>/dev/hdb2 = /myth/video
>>>etc...
>>>      
>>>
>>There have been a number of ways proposed.  My current thought of the
>>"best" is to allow you to create "storage groups".  You can add
>>directories to a storage group and list how much space in MB (or how
>>much to leave free on that directories partition).  When you record a TV
>>show you can have it save it to the general storage group, or have it
>>save it to a specific one.
>>
>>The difficulty in any mutliple directory approach is what happens when
>>you have 5 GB free in this directory, 20GB free in another, and 500K in
>>another.  Do we split up video streams, do we move files between them,
>>and so on.  a 4 hour HD show that's 36GB can be tricky.  If you had 6
>>drives and anywhere from 5GB to 20GB free, which do you store to?  Add
>>in auto-expire and it gets even more tricky.
>>    
>>
>please forgive my ignorance of the Linux filesystem, but i thought
>that if you had a directory, /myth for example, that the directories
>in it would shrink and grow accordingly unless you set them to
>particular partitions.  so /myth is on a 300GB partition and it
>contains /myth/tv.  /myth/tv will grow as long as there is room on the
>partition.
>i'm guessing that shrinking is the problem since that's been mentioned
>with XFS and JFS...
>so my /myth/tv directory will grow to 200GB and then i decide to
>delete all my content.  but with XFS /myth/tv is still 200GB in size
>even though it is empty?  so if i want to add my dvd collection i've
>only got ~50GB of space left even though i've deleted all the content
>in /myth/tv..?
>if this is the case then i guess one of my scenarios would still work,
>but it would use space rather inefficiently.
>maybe we need to bug IBM into making XFS (that's theirs right?) shrinkable. :)
>
>cool stuff.  it's funny how the more you play with your setup the more
>crazy ideas you get and the more stuff there appears to be done!
>
They were talkig about mounting partitions (or LVM's or RAID devices) in 
directories under the recordings directory and about resizing partitions 
(or LVM's or--to some extent-RAID devices).  If you want to resize a 
partition (or LVM or--if allowed--RAID device), you have to resize the 
filesystem on that partition (or LVM or RAID device), and some 
filesystems don't allow resizing.

However, if you delete 200GB of data from /myth/tv, then the filesystem 
on the partition (or LVM or RAID device) that contains /myth/tv now has 
200GB more space available--(almost) regardless of filesystem type 
(don't worry about the almost--any filesystem you're likely to use for 
Myth, and even ones you're not, will reclaim the space--including 
ext2/3, XFS, ReiserFS (even Reiser4), or JFS).

Mike