[mythtv-users] Best Filesystem Type?

[Michael T. Dean]

On 04/11/2007 03:36 AM, Brian Wood wrote:
> On Apr 10, 2007, at 11:21 PM, David Brodbeck wrote:
>> Robert Current wrote:
>>     
>>> I was reading about MythTV for a few days before installing, and I
>>> read because of the file size, ext2 and ext3 were not great choices,
>>> but JFS was great...
>> The main problem with ext3 is deletes of large files block access  
>> to the filesystem while they're in progress.  MythTV has a workaround for  
>> this called "slow deletes" that solves the problem.
>>     
> It "solves" the  problem only if Myth is the only program performing  
> deletes on that filesystem.
>   

But if you're using anything else to delete MythTV recordings, you're 
leaving orphans in the DB.  The /only/ thing that should ever delete 
MythTV recordings is MythTV.

If you store other things on the same drive, you could have issues, but 
chances are those other things are far smaller than MythTV recordings.  
Of course, if you do have other large things to store (i.e. ripped DVD 
ISO's in MythVideo, etc.), putting them on another drive is the best 
solution, anyway.  The only reason the MythTV recordings are typically 
put in the same drive/volume is because of its ability to write to only 
one recording directory, and the same doesn't apply to MythVideo.  The 
new-for-0.21-when-it's-released Storage Groups feature will make proper 
filesystem design easier, but I'm running my Myth box with 3TB of 
storage on 5 HDD's on 2 backends and I don't use any type of MD 
(LVM/RAID/...) and don't yet have Storage Groups.  See myth_archive_job.pl.

> But having said that, I've been using an EXT3 filesystem for over a  
> year with no problems, I'm just careful about not deleting anything  
> over an hour long if a recording is happening.
>   

I've been using ext3 for 3 years and haven't ever had issues (and for 
the last 6 months, I've had HDTV only--meaning 4-10GiB/hr).  Before slow 
deletes, I'd have a pause for a couple of seconds after a delete, but 
now--due to UI changes and slow deletes--even that's gone.

I delete before, during, and after recordings without issue.  The slow 
deletes make ext3 an excellent choice.

> The main thing about EXT3 is that the Linux support for it is stable  
> as heck and very well de-bugged on all platforms. Every other  
> filesystem is a crapshoot IMHO, even though they work well for a lot  
> of folks.

Totally agree.

Mike