Re: lvm-vdo, snapshots and cache
Gionatan Danti <[email protected]>
| Newsgroups | gmane.linux.lvm.general |
|---|---|
| Message-ID | <[email protected]> |
Il 2022-11-16 11:50 Zdenek Kabelac ha scritto: > Well - as said - vg on vg is basically equivalent of the original LV > on top of VDO manager. Hi Zdenek, it seems clunkier to manage two nested VG/LV if you ask me. > But still these fast snapshot do not solve you a problem of double > out-of-space fault. Yeah, but available space requires constant monitor even when dealing with lvmthin. > It's good for experimenting - but I'd not suggest to use this setup. In RHEL7 it was specifically supported - see here[1]: "As a general rule, you should place certain storage layers under VDO and others on top of VDO: Under VDO: DM-Multipath, DM-Crypt, and software RAID (LVM or mdraid). On top of VDO: LVM cache, LVM snapshots, and LVM Thin Provisioning" For a practical example: in the past I experimented with a storage stack composed of raid -> vdo -> lvmthin -> xfs serving qemu/kvm virtual disk files. The lvmthin layer enabled rolling snapshots, and was a key feature of the test setup. Now the only method to replicate that is to have two nested LVM instances, one running vdo and one lvmthin - right? Regards. [1] https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/storage_administration_guide/vdo-qs-requirements -- Danti Gionatan Supporto Tecnico Assyoma S.r.l. - www.assyoma.it email: [email protected] - [email protected] GPG public key ID: FF5F32A8 _______________________________________________ linux-lvm mailing list [email protected] https://listman.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/