[OpenIndiana-discuss] Layout of zfs fs

[Harry Putnam]

vab at bb-c.de (Volker A. Brandt) writes:

> Harry Putnam writes:
>> >> So should I create the zfs fs  by
>> >> zfs create ... -o mountpoint=/usr/local p0/local
>> >> zfs create ... p0/local/src
>> >> zfs create ... p0/local/src/git
>> >>
>> >> (the -p option may be useful above.. I just want it
>> >> to be clear what is being done)
>> >>
>> >> ending with /usr/local/src/git
>> >>
>> >> OR like this:
>> >>
>> >> zfs create ... -o mountpoint=/usr/local p0/local
>> >> zfs create ... -o mountpoint=/usr/local/src  p0/src
>> >> zfs create ... -o mountpoint=/usr/local/src/git  p0/git
>> >
>> > Certainly the former.  If you use the second version, all three moint-
>> > points will be "local".  In the first version, the second (src) and
>> > third mountpoints will be "inherited".
>> >
>> > So if you one day decide that you have seen the light and want to con-
>> > vert to The One True local Mountpoint as Our Lord Intended It, you can
>> > just change the first mount point to /opt/local, and the rest will
>> > automatically inherit the new setting.
>>
>> Thanks for your thoughts.
>>
>> Sounds like the inherited mount point rates pretty high in your notion
>> of what works best.
>>
>> I suspect you have other reasons as well, and I would like to hear
>> about them if you don't mind expounding a bit more.
>>
>> For example:
>> What baring[sp] would either way have on the ability to `send/receive'?
>>
>> I'm very inexperienced in send/receive:
>>
>> In the method you prefer, and the first on shown in OP, can $USER
>> `send/receive' the whole of `local/src/git' in one move?  Or would it
>> need to be broken down into three send/receive sessions?
>
> Both will work.  Any dataset snapshot can be sent/received separately,
> if you want.  But you can also use a recursive send where the dataset
> itself and all "child datasets" will be included in the stream.  Check
> out the "-r" and "-R" flags in the zfs(1M) man page.

I could not find an -r (lowercase) for send sub-command (maybe you are
only refering to zfs main cmd).  But experimenting with send -R I seem to have
gotten myself into some trouble.

I attempted to:
   zfs send -R rpool/export/home/MYUSER |ssh oi0 zfs recv p12x

where rpool is from  oi installed on hardware, and oi0 is oi running
on vbox vm on windows.  And p12x is a new pool on the vbox vm created
for this experimentation.

So the result was that rpool/export/home/MYUSER showed up on the VBox
instance of oi as p12x/export/home/MYUSER.   But it attempted to
retain the mountpoint from the sending os of /export/home/reader.
Fortunately the mount was unsucessful since MYUSER was not empty.

So the sent fs is setting there and can cbe displayed with
zfs list -r and shows the mountpoint that was refused as if it worked.

On receiving OS:

,----
|  root # zfs list -r p12x
|  NAME   USED  AVAIL  REFER  MOUNTPOINT
|  p12x  3.86G   203G  3.86G  /export/home/reader
| 
|  (Shows the data occupying 3.86 of space)
`----

However the fs p12x/export/home/MYSUSER will not accept substitute
mount point and claims the fs does not exist:

,----
|   On the recv OS:
|   I created an empty directory at /2x-rpool and tried:
|     (2x is hostname of sending OS) 
|      zfs set mountpoint=/2x-rpool p12x/export/home/reader
|   cannot open 'p12x/export/home/reader': dataset does not exist
`----

So I can't remount it. Or see the data in anyway I can think off.

zfs cannot even destroy it:

,----
|   On recv OS:
|     root # zfs destroy -r p12x/export/home/reader
|   cannot open 'p12x/export/home/reader': dataset does not exist
`----

Fortunately `zpool' still knew how:

,----
|   On recv OS:
|    zpool destroy p12x
|    (Finished with no errors)
`----

   zfs list -r shows it gone


So is there a way to send rpool to a remote host without all that mess?