[mythtv-users] What is best filesystem for recordings?

[Tim Draper]

---- On Tue, 30 Jun 2015 08:47:20 +0100 Warpme  wrote ---- 
>Hi * 
> 
>I just got some free space on my server (8T Seagate Archive for videos) 
>which temporarily gives me spare capacity allowing change filesystem for 
>recordings volumes. 
> 
>Currently I have 2x4T HDD allocated purely for recordings. Both volumes 
>are now on ext3. 
> 
>After years of relaying on ext3 I think it is not best filesystem for 
>recordings as: 
>-delete is very throughput expensive 
>-chkdsk is really long 
>-starting loosless cut makes hell of: 
>TFW(/myth/tv/21101_20150630054000.ts:67): write(57152) cnt 35 total 
>2079656 -- took a long time, 2571 ms 
> 
>So what FS will be better: XFS or JFS or ...? 
> 
>I think following criteria should be compared: 
>1.concurrency (frequently I have 8-10 concurrent HD recordings); 
>2.CPU consumption under high FS load; 
>3.reliability (I don't have UPS and sometimes power is lost when many 
>recordings are ongoing); 
>4.stability/maturity (i.e. recovery from bad/deep FS corruption); 
>5.any other I forgot.. 
> 
> 

i tried BTRFS about 9 months ago but found it to struggle under load. i moved from btrfs to jfs/xfs (i forget which) and it was a very noticeable improvement. I was having some BTRFS performance issues which i assumed was down to the mythtv media partition. I suspect i used XFS as i don't think JFS is natively out-the-box supported under Fedora which i now use.
Currently on ext4 that I've had 4 streams going to it (3x HD record, 1x HD livetv) and it didnt have any obvious visuals issues. 2disk mdadm raid1, LVM with 3x ext4 partitions.

Having just lost one of my raid1 disks (seagate 3tb fwiw) i'm currently seeing some 'took a long time' messages, but hoping that'll sort itself out when i go back to WD Reds tonight. Not something i've noticed in mythbackend logs prior to seeing a number of UNC disk errors in SMART data.