Re: [linux-lvm] Re: [linux-lvm] Verständnis von Stripes bei LVM

[svetljo <galia@st-peter.stw.uni-erlangen.de>]

it's probably a silly question, but what about

Re: [linux-lvm] diff. in striping between HP-UX and Linux LVM from Heinz 
Mauelshagen

probably it's better to have a linear LV over software RAID-0

Goetz Bock wrote:

>On Fri, Sep 14 '01 at 11:32, Pawlowski Julian wrote:
>
>>ich habe eine Frage zur Funktion von Stripes beim LVM. Wof�r genau
>>ben�tigt man diese Funktion? Wird damit das LV auf mehrere der reellen
>>Partitionen zwecks Performancegewinn verteilt?
>>
>Yes, that's exactly the intended bahaviour. if you have n (e.g. 2 or
>more) PV than a striped LV is splitted between this n PV. This can
>increase performance (like RIAD0 does) but it may backfire, if your PV
>are on the same reald device.
>If you want to use striped LVs, only use one PV per real device.
>
>e.g.: 4 HDDs of 40GB each (sda, sdb, sdc, sdd)
>
>you boot from sda and decide to have a 512MB root/boot partition for
>this. Than make 3 swap partitiones on sdb, sdc and sdd.
>
>on each device make a seccond partition with the rest of the space.
>create a PV out of each of this 4 partitions.
>
>you now have:
>
>sda: sda1    512MB  root/boot
>     sda2   39.5GB  PV1
>sdb: sdb1    512MB  swap
>     sdb2   39.5GB  PV2
>sdc: sdc1    512MB  swap
>     sdc2   39.5GB  PV3
>sdd: sdd1    512MB  swap
>     sdd2   39.5GB  PV4
>
>VG1:       118.0GB  PV1 PV2 PV3 PV4
>
>if you now make a striped LV of 20GB it will use 5GB on each PV and the
>stripes will be read from PV1 PV2 PV3 PV4 PV1 PV2 PV3 PV4 ...
>
>BTW: if you write your question in english a lot more people will be
>     able to send you a reply.
>
>PS: und wenn Du willst kann ich Dir das ganze gerne nochmal auf Deutsch
>    schicken.
>