[linux-lvm] stripped LV with segments vs one segment

[Zdenek Kabelac]

Dne 10.4.2017 v 11:29 lejeczek napsal(a):
> hi there
>
> I could not extend my stripped LV, had 3 stripes and wanted to add one more.
> Only way LVM let me do it was where I ended up with this:
>
>   --- Segments ---
>   Logical extents 0 to 751169:
>     Type        striped
>     Stripes        3
>     Stripe size        16.00 KiB
>     Stripe 0:
>       Physical volume    /dev/sdd
>       Physical extents    0 to 250389
>     Stripe 1:
>       Physical volume    /dev/sde
>       Physical extents    0 to 250389
>     Stripe 2:
>       Physical volume    /dev/sdc
>       Physical extents    0 to 250389
>
>   Logical extents 751170 to 1001559:
>     Type        linear
>     Physical volume    /dev/sdf
>     Physical extents    0 to 250389
>
> 1st question - was this really the only way LVM would extend?
> 2nd - is there performance penalty with segments like above vs one stripped
> segment?
>

Hi


Not really sure what you aim to do.

If you have LV segment with 3 stripes - you have to keep also extension using 
3 stripes -  you can't  have 1st. halve of LV spanning 3 disk and add there a 
new LV segment as linear - as listed in this post.

Both segments must by striped.

Regards

Zdenek