Re: How to properly resize VG/LV on LVM?

[Dima Veselov <kab00m%lich.phys.spbu.ru@localhost>]

On 03.08.2020 12:10, Bartosz Maciejewski wrote:

> I got logical volume for mailboxes on LVM for easy expanding as 
> mailboxes are growing. However I can't really resize it, or I don't know 
> how to do it on NetBSD.

Actually it is done the same anywhere. You have to enlarge every device
in the chain.

> Filesystem                            Size       Used Avail %Cap Mounted on
> /dev/mapper/varmailvg-virtuallv       984G       860G 74G  92% 
> /var/mail/virtual
>
> xbd3: 1200 GB, 512 bytes/sect x 2516582400 sectors
> # lvm pvresize /dev/rxbd3a

It seems your PV is located on NetBSD slice of xbd3, not on xbd3 itself. 
That means you have to enlarge slice using disklabel(8) first.

> which looks good, but lvm pvs still shows 1000GB instead of 1200GB
>
> # lvm pvs
>    PV          VG        Fmt  Attr PSize    PFree
>    /dev/rxbd3a varmailvg lvm2 a-   1000.00g 1020.00m
>
> Probably I should "resize in place" with disklabel or fstab after 
> extending in Xen but I don't know exactly how. There is also resize_ffs 
> somewhere in a process I think.
>
> Is there any guide for NetBSD how to properly extend lvm volume?

This job is always very local, I don't think one can create sufficient
documentation to cover all the possible options. However big document
can be found here https://www.netbsd.org/docs/guide/en/chap-lvm.html

--
Sincerely yours,
Dima Veselov
Physics R&D Establishment of Saint-Petersburg University