Hi Klaus,
i tried mhddfs since I've 5 disks with together 8 TB.
The problem is that mhddfs didn't run reliable for me.
I tried Debian Wheezy with kernel 3.2, 3.6, 3.10, but every time after starting an recording I got
vdr: [19801] ERROR (tools.c,423): /video1: Der Socket ist nicht verbunden/var/log/syslog.6.gz:Nov 24 19:54:38 video1 vdr: [20399] ERROR (recording.c,856): /video1/Spielfilm/Romantik~Liebe/Ein_verlockendes_Spiel/2011-12-11.20.05.8-0.rec/info: Der Socket ist nicht verbunden vdr: [20399] ERROR (recording.c,914): /video1/Spielfilm/Romantik~Liebe/Ein_verlockendes_Spiel/2011-12-11.20.05.8-0.rec/summary.vdr: Der Socket ist nicht verbunden vdr: [20399] ERROR (tools.c,613): /video1/Spielfilm/Romantik~Liebe/Ein_verlockendes_Spiel/2011-12-11.20.05.8-0.rec: Der Socket ist nicht verbunden vdr: [20431] ERROR (recorder.c,159): /video1/Doku/Natur/Terra_X:_Faszination_Erde_-_mit_Dirk_Steffens/Teil_:_Wildes_Mittelmeer_-_Wiege_Europas/2013-11-24.19.28.51-0.rec/00001.ts: Der Socket ist nicht verbunden vdr: [20397] ERROR (tools.c,423): /video1: Der Socket ist nicht verbunden
So I tried aufs. This works nearly great for me.
mount -t aufs -o br=/video1.1=rw:/video1.2=rw:/video1.3=rw:/video1.4=rw:/video1.0=rw -o create=mfsrr:$((10*1024*1024*1024)):30 -o udba=reval,sum,verbose none /video1
But now I cannot delete recordings from within vdr.
I found something about this:
http://aufs.sourceforge.net/aufs.html#Incompatible%20with%20an%20Ordinary%20...
To rename(2) directory may return EXDEV even if both of src and tgt are on the same aufs. When the rename-src dir exists on multiple branches and the lower dir has child(ren), aufs has to copyup all his children. It can be recursive copyup. Current aufs does not support such huge copyup operation at one time in kernel space, instead produces a warning and returns EXDEV. Generally, mv(1) detects this error and tries mkdir(2) and rename(2) or copy/unlink recursively. So the result is harmless. If your application which issues rename(2) for a directory does not support EXDEV, it will not work on aufs. Also this specification is applied to the case when the src directory exists on the lower readonly branch and it has child(ren).
Is it possible that vdr supports aufs?
aufs would be better than mhddfs: faster, not fuse, in kernel, under development...
Regards, Mike