Re: NetBSD's LVM works great for me

On 03/23/16 10:41, haad wrote:

Hi,

On Wed, Mar 23, 2016 at 3:55 PM, Swift Griggs <swiftgriggs%gmail.com@localhost> wrote:

On Wed, 23 Mar 2016, Stephen Borrill wrote:

It's been around since the -6 era, so it's not that new.

Ah, I see. For some reason, I never messed with it in 6.x. Sorry for the misinformation.

I don't think any major development has been done on LVM since it was committed which is a shame as, while solid, it has missing features as you describe.

>From what I can tell, it was done on a contract to Sistina Software UK. At least, that's what's in the man page. Maybe the maintainers/devs are $$$ only and so nobody has picked it up and gave the code a big hug, yet. I'm not complaining, just observing. I know it's a lot of work.

LVM support ws done by me. There was some work done by ahoka@ couple years ago on mirroring target but I never had time to merge it. That was major blocker to implement snapshots.

Well, thanks for your efforts :-) !!!!

Multipathing should not be that hard at least with some simple policies.

How about RAID5/10 ? Those seem to be in the more current Linux implementations, see http://man7.org/linux/man-pages/man8/lvcreate.8.html

I would add multipathing as a wish-list item too.

Oh, that would rock. Yes, indeed. On a more spacey note, I wish multipathing could be better handled by the hardware. Ie.. some firmware setting on a dual/quad-port HBA. I've seen this on crappy hardware-based iSCSI ethernet HBAs, but never for fiber. I guess that doesn't help much if you use discrete cards. Plus, software MPIO probably gives you a lot more options for load balancing et al.

Have you looked at HAST in FreeBSD?
https://wiki.freebsd.org/HAST

I had when they announced it but I forgot about it. Thanks for reminding me. Their page says they now have an async mode. I wonder how much it can buffer ala DRBD-proxy. I guess it's time to test it out and get some time on the metal so I know for sure. In my opinion, the holy grail for database servers is to have full-speed local access to storage, while keeping replicated to somewhere in Timbuktu in near-time for DR etc...

DRBD alternative would be much harder to implement.

--

Regards.

Adam

Thanks again for doing the heavy lifting on this feature.

-- 

	William A. Mahaffey III

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