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From: Zdenek Kabelac <zdenek.kabelac@gmail.com>
To: LVM general discussion and development <linux-lvm@redhat.com>,
	Gionatan Danti <g.danti@assyoma.it>
Subject: Re: [linux-lvm] lvm-vdo, snapshots and cache
Date: Tue, 15 Nov 2022 22:56:01 +0100	[thread overview]
Message-ID: <0c1d5e76-085c-cb46-c477-3bcd70a8acb2@gmail.com> (raw)
In-Reply-To: <8404c979411230748aa52deacca89cd8@assyoma.it>

Dne 15. 11. 22 v 18:42 Gionatan Danti napsal(a):
> Dear all,
> as previous vdo utils are gone in RHEL9, VDO volumes must be created via 
> lvm-vdo and associated lvm commands.
> 
> What is not clear to me is how to combine lvm-vdo with lvmthin (for fast CoW 
> snapshots) and/or lvmcache (for SSD caching of an HDD pool). For example, with 
> the old /dev/mapper/vdo style volumes (ie: the one created via vdo create) one 
> can do something as physical_dev -> vdo -> lvmthin -> lvmcache.
> 
> How to do the same with lvm-vdo?


Hi

You could try  'vg' on top of another 'vg' - however I'd not recommend to use 
it this way (and it's unssuported (&unsupportable) by lvm2 in general)

We aim to support multiple VDO LV within a single VDOPOOL - will hopefully 
happen relatively soon  (so it should work like with thin pools)

IMHO I'd not recommend to combine 2 provisioning technologies - it's already 
hard to resolve 'out-of-space' troubles with just one technology...

We will see if the 'VDO thick snapshot' will also go with multiple VDO LV 
support - likely not - but will be added later on.

Caching should be already support - on VDO LV as well as on VDOPOOL LV (both 
work somewhat differently).

Regards

Zdenek

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  reply	other threads:[~2022-11-15 21:56 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-15 17:42 [linux-lvm] lvm-vdo, snapshots and cache Gionatan Danti
2022-11-15 21:56 ` Zdenek Kabelac [this message]
2022-11-15 22:41   ` Gionatan Danti
2022-11-16 10:50     ` Zdenek Kabelac
2022-11-16 14:38       ` Gionatan Danti
2022-11-16 15:35         ` Zdenek Kabelac

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