Re: CVS commit: src/etc

[Alexander Nasonov <alnsn%yandex.ru@localhost>]

Brad Spencer wrote:
> Alexander Nasonov <alnsn%yandex.ru@localhost> writes:
> > Are there any downside of mixing legacy and non-legacy mountpoints?
> > E.g. if my /var is legacy but /var/crash is a normal ZFS mountpoint?
> 
> That should work fine as long as /var was arranged to be mounted first.
> The other way around may and probably is trouble right now, where a
> zpool Not-legacy needs to be mounted so that a ZFS legacy filesystem or,
> in fact, any other filesystem type gets mounted under it.  I believe
> that Solaris did and probably still does have this problem too.  Legacy
> ZFS mounts should be perfectly workable even from single user when /usr
> isn't available yet for most simple use cases.

Since I plan to migrate my ZFS setup to a smaller cgd disk, I gave
legacy mountpoints a try to see how much complexity they add.

I have the following ZFS mountpoints in my setup

/usr      - legacy
/var      - legacy
/var/log  - legacy
/var/tmp  - normal
/var/mail - normal
...

Ideally, I'd like to keep all datasets under one root:

tank/base/usr      - legacy
tank/base/var      - legacy
tank/base/var/log  - legacy
tank/base/var/mail - normal

but it has a small inconvenience: every time I add a new dataset under
a legacy mountpoint (e.g. create a dataset for /var/spool), it can't
inherit a mountpoint from a legacy mountpoint and I have to set it
manually (zfs set mountpoint=/var/spool tank/base/var/spool).

One way to avoid this issue is to have separate hierarchies:

tank/legacy
tank/legacy/usr
tank/legacy/var
tank/legacy/var/log
tank/base
tank/base/var
tank/base/var/mail

but I'm pretty sure it has some downsides too.

Alex