* [linux-lvm] Boot Mgr support for '/boot' on LVM2 volumes ?
@ 2006-03-05 16:46 John Smith
2006-03-07 19:06 ` Luca Berra
0 siblings, 1 reply; 6+ messages in thread
From: John Smith @ 2006-03-05 16:46 UTC (permalink / raw)
To: linux-lvm
Hi.
I was wondering if booting from an LVM2 volume group is supposed to be
supported with lilo (preferred) or GRUB. For example, is it supported
to use a '/boot' device, when that is a LVM2 volume residing in an
LVM2 volume group ?
Last time I checked, having /boot on a LVM2 device using lilo was
still considered 'unsupported', or at least considered to be "not a
very good idea". If I recall correctly, this had something to do with
the fact that "/boot" had to be located on a linear, contiguous volume
for bootloaders like lilo and grub to be able to read it. And that
with something like LVM, it's on very easy for a volume to be
non-contiguous.
Is this still the case with the current release of LVM2, or has this
been worked-around in current releases ?
Sincerely,
John Smith.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [linux-lvm] Boot Mgr support for '/boot' on LVM2 volumes ?
2006-03-05 16:46 [linux-lvm] Boot Mgr support for '/boot' on LVM2 volumes ? John Smith
@ 2006-03-07 19:06 ` Luca Berra
2006-03-07 21:21 ` John Smith
2006-03-25 17:31 ` [linux-lvm] " Claus Färber
0 siblings, 2 replies; 6+ messages in thread
From: Luca Berra @ 2006-03-07 19:06 UTC (permalink / raw)
To: linux-lvm
On Sun, Mar 05, 2006 at 05:46:45PM +0100, John Smith wrote:
>still considered 'unsupported', or at least considered to be "not a
Christophe Saout made some patches to lilo to be able to boot from a
lvm2 /boot (http://www.saout.de/misc/), this patch has been adopted into
major distributions.
>very good idea". If I recall correctly, this had something to do with
>the fact that "/boot" had to be located on a linear, contiguous volume
>for bootloaders like lilo and grub to be able to read it. And that
this is correct, the lv for /boot is to be linear and contiguus, it is
user responsability to ensure this.
L.
--
Luca Berra -- bluca@comedia.it
Communication Media & Services S.r.l.
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [linux-lvm] Boot Mgr support for '/boot' on LVM2 volumes ?
2006-03-07 19:06 ` Luca Berra
@ 2006-03-07 21:21 ` John Smith
2006-03-08 20:43 ` Luca Berra
2006-03-25 17:31 ` [linux-lvm] " Claus Färber
1 sibling, 1 reply; 6+ messages in thread
From: John Smith @ 2006-03-07 21:21 UTC (permalink / raw)
To: LVM general discussion and development
On 3/7/06, Luca Berra <bluca@comedia.it> wrote:
>
> Christophe Saout made some patches to lilo to be able to boot from a
> lvm2 /boot (http://www.saout.de/misc/), this patch has been adopted into
> major distributions.
>
Cool, I didnt know that.
>
> this is correct, the lv for /boot is to be linear and contiguus, it is
> user responsability to ensure this.
>
UUhhmm...Ok, now im confused. If 'the user' still has to make sure
that /boot is linear and contiguous, then :
1.) Exactly, what, does the patch *do* then ?
2.) How does 'the user' (me, in this case) ensure this ?
Sincerely,
John Smith.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [linux-lvm] Boot Mgr support for '/boot' on LVM2 volumes ?
2006-03-07 21:21 ` John Smith
@ 2006-03-08 20:43 ` Luca Berra
0 siblings, 0 replies; 6+ messages in thread
From: Luca Berra @ 2006-03-08 20:43 UTC (permalink / raw)
To: LVM general discussion and development
On Tue, Mar 07, 2006 at 10:21:49PM +0100, John Smith wrote:
>On 3/7/06, Luca Berra <bluca@comedia.it> wrote:
>>
>> Christophe Saout made some patches to lilo to be able to boot from a
>> lvm2 /boot (http://www.saout.de/misc/), this patch has been adopted into
>> major distributions.
>>
>Cool, I didnt know that.
>
>>
>> this is correct, the lv for /boot is to be linear and contiguus, it is
>> user responsability to ensure this.
>>
>UUhhmm...Ok, now im confused. If 'the user' still has to make sure
>that /boot is linear and contiguous, then :
>1.) Exactly, what, does the patch *do* then ?
it allows lilo to query device mapper and map a dm device to physical
sectors on the disk.
>2.) How does 'the user' (me, in this case) ensure this ?
>
make /boot a separate logical volume than /
do not extend it.
L.
--
Luca Berra -- bluca@comedia.it
Communication Media & Services S.r.l.
/"\
\ / ASCII RIBBON CAMPAIGN
X AGAINST HTML MAIL
/ \
^ permalink raw reply [flat|nested] 6+ messages in thread
* [linux-lvm] Re: Boot Mgr support for '/boot' on LVM2 volumes ?
2006-03-07 19:06 ` Luca Berra
2006-03-07 21:21 ` John Smith
@ 2006-03-25 17:31 ` Claus Färber
2006-03-30 21:59 ` Alasdair G Kergon
1 sibling, 1 reply; 6+ messages in thread
From: Claus Färber @ 2006-03-25 17:31 UTC (permalink / raw)
To: linux-lvm
Luca Berra schrieb:
> this is correct, the lv for /boot is to be linear and contiguus, it is
> user responsability to ensure this.
What about adding a "boot" flag to LVs? It set, it could have the
following effect:
. Tools will ensure that the LV remains linear and contiguus and at the
beginning of a PV.
. (Later) the LV is mirrored into every PV marked "bootable".
With these features, an OS could be booted from any disk. With mirroring
(RAID-on-LVM) you could boot a system even if your primary disk fails.
Claus
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2006-03-30 21:59 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2006-03-05 16:46 [linux-lvm] Boot Mgr support for '/boot' on LVM2 volumes ? John Smith
2006-03-07 19:06 ` Luca Berra
2006-03-07 21:21 ` John Smith
2006-03-08 20:43 ` Luca Berra
2006-03-25 17:31 ` [linux-lvm] " Claus Färber
2006-03-30 21:59 ` Alasdair G Kergon
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