Re: [HEADS UP] Merge of projects/gvinum to head

On Tue, March 17, 2009 11:39, Ulf Lilleengen wrote:
> On tir, mar 17, 2009 at 09:52:31am -0300, Nenhum_de_Nos wrote:
>>
>> On Tue, March 17, 2009 06:49, Ulf Lilleengen wrote:
>> > On man, mar 16, 2009 at 11:07:12pm -0300, Nenhum_de_Nos wrote:
>> >>
>> >> On Mon, March 16, 2009 12:59, Ulf Lilleengen wrote:
>> >> > On man, mar 16, 2009 at 04:58:00pm +0100, Ulf Lilleengen wrote:
>> >> >> Hello,
>> >> >>
>> >> >> This is a heads-up for a merge of gvinum project code into HEAD.
>> This
>> >> >> means
>> >> >> that gvinum implementation will be changed some. The code is based
>> on
>> >> >> the
>> >> >> work done by Lukas Ertl as well as the work I did before/during
>> >> Google
>> >> >> SoC
>> >> >> 2007 and afterwards. It has been staying in p4 for some time, and
>> >> then
>> >> >> moved
>> >> >> to the subversion project repository not long ago. The main reason
>> >> for
>> >> >> the
>> >> >> delay of getting this into HEAD have been the lack of reviewers of
>> >> the
>> >> >> code,
>> >> >> but after some discussion and help from testers, I've decided this
>> is
>> >> a
>> >> >> good
>> >> >> time to get it in (should perhaps have been merged a bit earlier)
>> >> >> Testers
>> >> >> have spotted several differences from the original gvinum, and
>> I've
>> >> >> tried to
>> >> >> make it behave as the old implementation wherever that seemed the
>> >> best
>> >> >> way to
>> >> >> go. Luckily, the work has gotten a bit of attention lately, thanks
>> to
>> >> >> Rick C.
>> >> >> Petty for helping out with testing and bugfixing, as well as all
>> >> others
>> >> >> who
>> >> >> have dared to run the new gvinum. So, what does this update offer?
>> >> >
>> >> > And I plan on importing it within 1-2 weeks :)
>> >>
>> >> great work, thanks.
>> >>
>> >> what's the status of raid5 ? is it ok to production enviroments ? I
>> have
>> >> been using gmirror and gstripe just cause I can't do raid5 and I'm
>> >> waiting
>> >> for ZFS to hit production state.
>> >>
>> > I would say that since the raid5 code hasn't changed much in terms of
>> > functionality, meaning that much of the code concerning raid5 is the
>> same,
>> > it
>> > should provide at least the same production quality as gvinum in 7.x.
>> What
>> > are your experiences with gvinum raid5 in 7.x?
>>
>> none, as I always read that the code was not ok or was not doing what
>> raid5 is all about (those parity counts), I never was brave enough to
>> try
>> it. is this all wrong ?
>>
> I've not heard of any issues with the actual raid5 algorithms to be wrong,

no, no, not wrong, but not implemented.

so, if I use raid5 now (must see docs to know how to) it will do its job
right if I replace one disk ? (as if one would die)

thanks,

matheus

> only gvinum being a bit to sensitive when doing administrative stuff like
> switching disks etc. as it would crash if you didn't do things in the
> correct
> order etc.  I've used it on a few storage servers without any problems
> directly related to raid5.
>
> --
> Ulf Lilleengen
>


-- 
We will call you cygnus,
The God of balance you shall be