zfs filesystem disappear from df and zdb

[tntteam22]

Hi,

Using Version: 0.6.9-1 zfs-fuse on ubuntu server 11.04 natty 64 bits

I created a zfs pool named datapool using /dev/sdb, activated compression and deduplication
Making a df and zdb-DD datapool works.
1 day after, df don't show the partition mounted, and zdb don't find /var/lib/zfs/zpool.cache :

root@srv:/datapool# zdb
cannot open '/var/lib/zfs/zpool.cache': No such file or directory

BUT I can still access /datapool and datas inside...

using
root@srv:/datapool# zpool import datapool
cannot import 'datapool': pool may be in use from other system, it was last accessed by supervision (hostid: 0x7f0101) on Tue Sep 27 14:52:55 2011
use '-f' to import anyway

After a reboot, df and zdb still don't show my datapool, but the filesystem is mounted and accessible.

...?

root@srv:/datapool# apt-cache policy zfs-fuse
zfs-fuse:
  Installed: 0.6.9-1
  Candidate: 0.6.9-1
  Version table:
 *** 0.6.9-1 0
        500 http://fr.archive.ubuntu.com/ubuntu/ natty/universe amd64 Packages
        100 /var/lib/dpkg/status

[tntteam22 (tntteam22)]

Here is how I did setup my zfs system :

aptitude install zfs-fuse
zpool create datapool /dev/sdb
zfs set dedup=on datapool
zfs set compression=on datapool

edit /etc/zfs/zfsrc :
max-arc-size = 100 -> max-arc-size = 2048

reboot

[tntteam22 (tntteam22)]

Ok I think I got it.. at least why.

In fact my /datapool is not mounted at all, and zfs won't mount it.

I think all this is because some services in init scripts uses data that are on my /datapool dir, but the zfs mount comes AFTER these services are loaded.

So it doesn't mount anything.

And my services are working because they are using /datapool as a regular directory and I didn't see it...

A simple copy paste of a big file from / to /datapool and seee that it made no changes to root / usage with df made me realize it.

How can we make zfs load before any service ?

[tntteam22 (tntteam22)]

Err, clearing my /datapool dir, and then mounting my zfs pool worked, reboot and still works.

So it's just disappearing randomly after some time ?