Re: Overhead of LVM (Re: Upgrade Problem)

[rhkramer@gmail.com]

On Friday, January 04, 2019 08:23:59 AM Reco wrote:
> # pvs
>   PV             VG     Fmt  Attr PSize  PFree
>   /dev/md10      nas    lvm2 a--  14.55t 10.43t
> 
> # hdparm -Tt /dev/md10
> /dev/md10:
>  Timing cached reads:   1224 MB in  2.00 seconds = 612.05 MB/sec
>  Timing buffered disk reads: 1210 MB in  3.00 seconds = 403.28 MB/sec
> 
> # hdparm -Tt /dev/nas/root
> /dev/nas/root:
>  Timing cached reads:   1224 MB in  2.00 seconds = 611.55 MB/sec
>  Timing buffered disk reads: 1154 MB in  3.00 seconds = 384.42 MB/sec
> 
> I see a difference, but I's something I can live with.

Thanks very much!

 I need to learn more about pvs (I did google the man page), but I assume the 
/dev/md10 and /dev/nas/root are two ways of referring to the same partition, 
one within LVM, and one not?