[lug] Using Loopback for /boot?

Davide Del Vento davide.del.vento at gmail.com
Wed Oct 23 13:23:55 MDT 2013


I don't have the answers to your "pressing" questions, but here are my "gut
feelings":

1) I doubt loopback would work in the early stage of the boot (e.g.
encryption doesn't)
2) I believe using your existing boot put you at higher risk of causing
problems than the solutions you believe are more risky (i.e. creating a new
partition or using a single partition)
3) deleting one partition and creating two (or more) new ones in that space
is a piece of cake and has never failed for me (out of maybe 50 or so times
I've done it since the late 90s). That does not mean it will not fail on
you, of course. And of course you have to pick the RIGHT partition to
delete, if you pick the WRONG one, all your data is gone (but that's true
even without the re-partitioning, since you will format it)

Regarding your other question "how many people here no longer use a
separate /boot?" I guess you have to specify "for what purpose".
In the last 5 years I've not used separate /boot partitions for my laptops
and desktops (about 6 machines, about 3-4 installs on each, the first on
each after wiping out windows, the other doing something similar to what
you are doing now). I've never experienced any problem with my approach. In
this timeframe I've not done any server install.

Finally, the link I gave does not simply claim your quote. It's a
discussion among people and one person claims that. Other people claim
different things. I claim that a /boot partition is unnecessary, in my
experience for my use case (which is for a home/office use).

Cheers,
Davide


On Wed, Oct 23, 2013 at 12:56 PM, <stimits at comcast.net> wrote:

> Actually, I forgot to add one option, as per the thread title...I was also
> considering if I could create a loopback mounted file from the existing
> /boot. E.G., create a file and format it under loopback, then use that
> during the install...the file would be on the original /boot, and act
> something like a jail to prevent interacting with other files. Not sure if
> during install there would be that kind of ability to name a loopback file
> as a /boot install, although I could create the file before install.
>
> As for a new separate partition, all current partitions are what I have. I
> do not use lvm, and repartitioning a partition in the middle of the others
> without touching those surrounding it is a possibility, but this too
> worries me. Simply making a new partition if there were space at the end of
> the drive would not be an issue, and due to losing data before manipulating
> a partition in the middle worries me when I can't afford to lose anything.
>
> But...making an install to a new subdirectory of the existing /boot seems
> to be perfect. However, I'm wondering if this is compatible with chain
> loading...it's been years since I messed with such boot details, but I am
> thinking there may be requirements of where files are placed in /boot
> relative to PBR. The motherboard is about 4 years old, so I'm assuming this
> is not likely an issue.
>
> I should state that my real question is "what are the safe ways of using
> the existing /boot *partition* and grub2 to not risk the existing linux
> install and existing windows 7 install". I'm very weary of any downtime, or
> any install method which could prove risky to any data. What are the risks
> of manipulating a non-lvm unused partition in the middle of the disk? What
> are the risks of installing a second fedora using the exact same /boot?
>
> The web link you gave does inspire me to simply install everything on one
> partition...it claims:
>    This is a holdover from "ye olde tymes"
> ...how many people here no longer use a separate /boot? Alternately, if I
> installed everything to a single root partition, and then eventually
> satisfied myself that all things are copied over and I was willing to
> destroy the old f16 and its /boot, how hard is it to migrate from one /boot
> directory on the root partition to a separate /boot partition (thus
> overwriting the old f16 /boot)?
>
> I guess the ideal situation would be that a separate /boot partition
> really does no longer have any meaning or advantage.
>
>
> ----- Original Message -----
> From: Davide Del Vento **
> To: Boulder (Colorado) Linux Users Group -- General Mailing List **
> Sent: Wed, 23 Oct 2013 18:30:30 -0000 (UTC)
> Subject: Re: [lug] Using Loopback for /boot?
>
> Why do you want to *share* boot?
> If I were you in your shoes I'd just make another *separate* boot
> partition (mounted as /boot in F19 and something like /f19boot in F16) and
> use that instead. Or even do not make a /boot partition at all, of course
> this has pros and cons as you probably know
> http://unix.stackexchange.com/questions/256/is-it-good-to-make-a-separate-partition-for-boot
>
>
>
>
> On Wed, Oct 23, 2013 at 12:15 PM,  <stimits at comcast.net> wrote:
>
>>
>>
>> Hi,
>>
>> I have an older machine with hardware issues on SATA ports which means
>> the two disks I have now are the only disks I can attach. I'm interested in
>> installing a newer version of fedora 19 (it has an existing fedora 16
>> install) to a spare 300 GB partition. The trick is that I have only one
>> /boot, and I do not want to harm the older install until I'm sure
>> everything is up and running on the newer install. The /boot/grub2/ is what
>> worries me.
>>
>>
>>
>> Current layout is no lvm used (just ordinary partitions). Drives: first
>> SATA drive contains windows 7 and linux swap (sda), while the second hard
>> drive contains fedora 16 and /boot (sdb). Second drive also contains the
>> spare 300 GB partition (sdb), currently formatted ext4. My desire is to
>> install fedora 19 to the spare sdb, share the /boot and swap, and either
>> edit the existing grub boot from old fedora 16, or replace it with the new
>> fedora 19 grub boot, with windows 7 and all linux installs remaining
>> bootable with no down time. FYI, without everything remaining on the
>> existing drive, I cannot add a new drive without replacing the motherboard.
>>
>>
>>
>> I suspect I can simply install fedora 19 and tell it to not format /boot,
>> then tell it to install on MBR of sda, or possibly even tell it to not even
>> install boot to MBR, but instead edit the grub boot menu. Kernels
>> themselves would not be overwritten due to version naming, but I still
>> worry about grub issues. Can anyone give me advice on how dangerous this
>> scheme is to damaging any of the existing operating systems? Or insights on
>> using a single /boot for two fedora installs? I'm trying to avoid putting
>> /boot on the same partition as / for the new install, but perhaps this
>> would be the only way.
>>
>>
>>
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>
>
>
> ****
>
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