On Thursday October 25, david@xxxxxxxxxxxx wrote:
>
> I didn't get a reply to my suggestion of separating the data and location...
No. Sorry.
>
> ie not talking about superblock versions 0.9, 1.0, 1.1, 1.2 etc but a data
> format (0.9 vs 1.0) and a location (end,start,offset4k)?
>
> This would certainly make things a lot clearer to new (and old!) users:
>
> mdadm --create /dev/md0 --metadata 1.0 --meta-location offset4k
> or
> mdadm --create /dev/md0 --metadata 1.0 --meta-location start
> or
> mdadm --create /dev/md0 --metadata 1.0 --meta-location end
I'm happy to support synonyms. How about
--metadata 1-end
--metadata 1-start
??
>
> resulting in:
> mdadm --detail /dev/md0
>
> /dev/md0:
> Version : 01.0
> Metadata-locn : End-of-device
It already lists the superblock location as a sector offset, but I
don't have a problem with reporting:
Version : 1.0 (metadata at end of device)
Version : 1.1 (metadata at start of device)
Would that help?
> Creation Time : Fri Aug 4 23:05:02 2006
> Raid Level : raid0
>
> You provide rational defaults for mortals and this approach allows people like
> Doug to do wacky HA things explicitly.
>
> I'm not sure you need any changes to the kernel code - probably just the docs
> and mdadm.
True.
>
> >> It is conceivable that I could change the default, though that would
> >> require a decision as to what the new default would be. I think it
> >> would have to be 1.0 or it would cause too much confusion.
> >
> > A newer default would be nice.
>
> I also suspect that a *lot* of people will assume that the highest superblock
> version is the best and should be used for new installs etc.
Grumble... why can't people expect what I want them to expect?
>
> So if you make 1.0 the default then how many users will try 'the bleeding edge'
> and use 1.2? So then you have 1.3 which is the same as 1.0? Hmmmm? So to quote
> from an old Soap: "Confused, you will be..."
:-)
NeilBrown
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