Re: [RFR] templates://partman-zfs/partman-zfs.templates

[Justin B Rye <jbr@edlug.org.uk>]

Christian PERRIER wrote:
> (please keep -boot CC'ed to answers)
[...]
> Template: partman-zfs/multipv_root
> Type: error
> # :sl4:
> Description: Separate /boot mandatory for this ZFS configuration
>  The ZFS pool where your root file system is hosted is configured to use more
>  than one physical volume.
>  .
>  With the exception of Mirror mode, configurations with multiple volumes
>  (Striped or RAID-Z) are not supported by the boot loader.
>  .
>  You should use a separate /boot partition in another ZFS
>  pool in Mirror mode or with another file system, such as UFS.

I'm not sure I follow the logic here.  The second paragraph seemed
to say that a multivolume ZFS pool in Mirror mode was okay, so if I'm
using that, why do I need to create a separate /boot partition?  And
if I create that partition on a new ZFS pool that's confined to one
volume, does it really matter what mode it's in? 

I'm guessing it should say something like:

   Your root file system is on a ZFS pool that uses more than one
   physical volume. The boot loader only supports this configuration
   for pools in Mirror mode, not Striped or RAID-Z modes.
   .
   Make sure /boot is on a partition using a supported ZFS pool
   configuration, or a different file system such as UFS.
 
> Template: partman-zfs/multipv_boot
> Type: error
> # :sl4:
> Description: Unsupported multiple volume ZFS for /boot
>  The ZFS pool where your /boot file system is hosted is configured to use more
>  than one physical volume.
>  .
>  With the exception of Mirror mode, configurations with multiple volumes
>  (Striped or RAID-Z) are not supported by the boot loader.
>  .
>  The /boot partition should use a separate ZFS pool or another
>  file system, such as UFS.

Oh!  I've ended up with suggested long-description text for
multipv_root that also works as-is for multipv_boot.  Though maybe
that's a sign it isn't specific enough.

[...]
> Template: partman-zfs/lowmem
> Type: boolean
> # :sl4:
> _Description: Go back to the menu and correct this problem?
>  You have configured one or more partitions with the ZFS file
>  system. Using ZFS on a computer with less than 512 Mb of memory
                                                      MB
>  may lead to stability problems and is not recommended.
[...] 
> Template: partman-zfs/vgcreate_multipv
> Type: select
> Choices: ${MULTIPV_CHOICES}
> # :sl4:
> _Description: Multidisk mode for this ZFS pool:
>  Please chose the mode  for multidisk operations for this ZFS pool:
                        ^^
>   - Striped: (default) data is spread across the physical volumes.
>              Similar to RAID 0;
>   - Mirror:  data is replicated to each physical volume.
>              Similar to RAID 1;
>   - RAID-Z:  some physical volumes store parity bits and data is
>              spread across others.
>              Similar to RAID 5 or RAID 6.

Well, normally we'd recommend asterisks as bullets.  And it seems odd
to put a semicolon on the end of the list item when it has already
contained a period.  Actually, how about:

    * Striped: similar to RAID 0 (default) - data is spread across the
               physical volumes;
    * Mirror:  similar to RAID 1 - data is replicated to each physical
               volume;
    * RAID-Z:  similar to RAID 5 or RAID 6 - some physical volumes
               store parity bits and data is spread across others.

-- 
JBR	with qualifications in linguistics, experience as a Debian
	sysadmin, and probably no clue about this particular package