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* Store on separate partition
@ 2016-08-24  7:06 Carlos Sánchez de La Lama
  2016-08-24  7:35 ` Vincent Legoll
  2016-08-24  8:18 ` Alex Kost
  0 siblings, 2 replies; 11+ messages in thread
From: Carlos Sánchez de La Lama @ 2016-08-24  7:06 UTC (permalink / raw)
  To: guix-devel

Hi all,

my (not very big) root partition is almost full, even after
garbage-collecting. I am trying to move the store to a separate
partition, but this is problematic as you need the store at boot time
for the system utilities (and to mount partitions, actually).

Is there a known way to achieve this?

Thanks!

Carlos

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-08-24  7:06 Store on separate partition Carlos Sánchez de La Lama
@ 2016-08-24  7:35 ` Vincent Legoll
  2016-08-24  8:18 ` Alex Kost
  1 sibling, 0 replies; 11+ messages in thread
From: Vincent Legoll @ 2016-08-24  7:35 UTC (permalink / raw)
  To: Carlos Sánchez de La Lama; +Cc: guix-devel

Hello,

> my (not very big) root partition is almost full, even after
> garbage-collecting. I am trying to move the store to a separate
> partition, but this is problematic as you need the store at boot time
> for the system utilities (and to mount partitions, actually).

I did it once and it worked (if I remember right) and I think it's because
all the required tools for mounting it are in the initrd...

But I did it at installation time, and not afterwards.

Maybe I misremember...

-- 
Vincent Legoll

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-08-24  7:06 Store on separate partition Carlos Sánchez de La Lama
  2016-08-24  7:35 ` Vincent Legoll
@ 2016-08-24  8:18 ` Alex Kost
  2016-08-24 10:37   ` Carlos Sánchez de La Lama
  2016-08-29 16:15   ` Ludovic Courtès
  1 sibling, 2 replies; 11+ messages in thread
From: Alex Kost @ 2016-08-24  8:18 UTC (permalink / raw)
  To: Carlos Sánchez de La Lama; +Cc: guix-devel

Carlos Sánchez de La Lama (2016-08-24 10:06 +0300) wrote:

> Hi all,
>
> my (not very big) root partition is almost full, even after
> garbage-collecting. I am trying to move the store to a separate
> partition, but this is problematic as you need the store at boot time
> for the system utilities (and to mount partitions, actually).
>
> Is there a known way to achieve this?

I tried to do it recently but failed.  My understanding is that it's
impossible, but I may be wrong.

-- 
Alex

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-08-24  8:18 ` Alex Kost
@ 2016-08-24 10:37   ` Carlos Sánchez de La Lama
  2016-08-25 14:30     ` Tomáš Čech
  2016-08-29 16:15   ` Ludovic Courtès
  1 sibling, 1 reply; 11+ messages in thread
From: Carlos Sánchez de La Lama @ 2016-08-24 10:37 UTC (permalink / raw)
  To: Alex Kost; +Cc: guix-devel

>> my (not very big) root partition is almost full, even after
>> garbage-collecting. I am trying to move the store to a separate
>> partition, but this is problematic as you need the store at boot time
>> for the system utilities (and to mount partitions, actually).
>
> I tried to do it recently but failed.  My understanding is that it's
> impossible, but I may be wrong.

After giving it some more thinking, I also think this is not
possible. The kernel image itself is in the store (and must be, because
you can have several system generations, each using a different
kernel). Same with initrd images.

I have finally moved the whole root to a bigger disk, not much different
to moving the store as root size (aside from the store) is rather small.

Thanks!

Carlos

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-08-24 10:37   ` Carlos Sánchez de La Lama
@ 2016-08-25 14:30     ` Tomáš Čech
  2016-08-25 22:04       ` Tomáš Čech
  0 siblings, 1 reply; 11+ messages in thread
From: Tomáš Čech @ 2016-08-25 14:30 UTC (permalink / raw)
  To: guix-devel

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On Wed, Aug 24, 2016 at 12:37:49PM +0200, Carlos Sánchez de La Lama wrote:
>>> my (not very big) root partition is almost full, even after
>>> garbage-collecting. I am trying to move the store to a separate
>>> partition, but this is problematic as you need the store at boot time
>>> for the system utilities (and to mount partitions, actually).
>>
>> I tried to do it recently but failed.  My understanding is that it's
>> impossible, but I may be wrong.
>
>After giving it some more thinking, I also think this is not
>possible. The kernel image itself is in the store (and must be, because
>you can have several system generations, each using a different
>kernel). Same with initrd images.
>
>I have finally moved the whole root to a bigger disk, not much different
>to moving the store as root size (aside from the store) is rather small.

I think it is impossible now but to achieve that you'd need only:

1] to store /gnu/store on separate partition (so grub will find it with its --search)
2] and have some bind mounts ready in initrd stage.

It would be nice to have more flexibility in this area.

Best regards,

S_W

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^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-08-25 14:30     ` Tomáš Čech
@ 2016-08-25 22:04       ` Tomáš Čech
  0 siblings, 0 replies; 11+ messages in thread
From: Tomáš Čech @ 2016-08-25 22:04 UTC (permalink / raw)
  To: guix-devel

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On Thu, Aug 25, 2016 at 04:30:37PM +0200, Tomáš Čech wrote:
>On Wed, Aug 24, 2016 at 12:37:49PM +0200, Carlos Sánchez de La Lama wrote:
>>>>my (not very big) root partition is almost full, even after
>>>>garbage-collecting. I am trying to move the store to a separate
>>>>partition, but this is problematic as you need the store at boot time
>>>>for the system utilities (and to mount partitions, actually).
>>>
>>>I tried to do it recently but failed.  My understanding is that it's
>>>impossible, but I may be wrong.
>>
>>After giving it some more thinking, I also think this is not
>>possible. The kernel image itself is in the store (and must be, because
>>you can have several system generations, each using a different
>>kernel). Same with initrd images.
>>
>>I have finally moved the whole root to a bigger disk, not much different
>>to moving the store as root size (aside from the store) is rather small.
>
>I think it is impossible now but to achieve that you'd need only:
>
>1] to store /gnu/store on separate partition (so grub will find it with its --search)
>2] and have some bind mounts ready in initrd stage.
>
>It would be nice to have more flexibility in this area.

According to
https://www.gnu.org/software/guix/manual/guix.html#File-Systems it
seems that 'bind-mount' is supported flag so together with
'needed-for-boot?' it should be doable.

normal mount
/dev/sdX --> /mnt/store-partition

bind mount
/mnt/store-partition/gnu --> /gnu

grub should find your kernel and initrd with --search

S_W

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^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-08-24  8:18 ` Alex Kost
  2016-08-24 10:37   ` Carlos Sánchez de La Lama
@ 2016-08-29 16:15   ` Ludovic Courtès
  2016-08-31 12:48     ` Carlos Sánchez de La Lama
  1 sibling, 1 reply; 11+ messages in thread
From: Ludovic Courtès @ 2016-08-29 16:15 UTC (permalink / raw)
  To: Alex Kost; +Cc: guix-devel

Hello,

Alex Kost <alezost@gmail.com> skribis:

> Carlos Sánchez de La Lama (2016-08-24 10:06 +0300) wrote:
>
>> Hi all,
>>
>> my (not very big) root partition is almost full, even after
>> garbage-collecting. I am trying to move the store to a separate
>> partition, but this is problematic as you need the store at boot time
>> for the system utilities (and to mount partitions, actually).
>>
>> Is there a known way to achieve this?
>
> I tried to do it recently but failed.  My understanding is that it's
> impossible, but I may be wrong.

It would be interesting to fix it.  In theory there’s no reason why it
shouldn’t work (you need to mark the /gnu/store file system as
‘needed-for-boot?’.)

If you or Carlos could try it and report details to bug-guix@gnu.org, we
could start from there.

Thanks!

Ludo’.

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-08-29 16:15   ` Ludovic Courtès
@ 2016-08-31 12:48     ` Carlos Sánchez de La Lama
  2016-08-31 21:21       ` Ludovic Courtès
  0 siblings, 1 reply; 11+ messages in thread
From: Carlos Sánchez de La Lama @ 2016-08-31 12:48 UTC (permalink / raw)
  To: Ludovic Courtès; +Cc: guix-devel, Alex Kost, bug-guix

>>> I am trying to move the store to a separate partition, but this is
>>> problematic as you need the store at boot time for the system
>>> utilities (and to mount partitions, actually).
>>>
>> I tried to do it recently but failed.  My understanding is that it's
>> impossible, but I may be wrong.
>
> It would be interesting to fix it.  In theory there’s no reason why it
> shouldn’t work (you need to mark the /gnu/store file system as
> ‘needed-for-boot?’.)
>
> If you or Carlos could try it and report details to bug-guix@gnu.org, we
> could start from there.

I got it more-or-less working. What I did is a plain 0.11 install, but
before the "herd start cow-store /mnt" step I had prepared the target
filesystems so I had:

/dev/sda1 mount as /mnt
/dev/sdb1 mounted as /mnt/gnu

To make the store go into /dev/sdb1

My system definition included:

--8<---------------cut here---------------start------------->8---
  (file-systems (cons* (file-system
                         (device "my-root")
                         (title 'label)
                         (mount-point "/")
                         (type "ext4"))
                       (file-system
                         (device "/dev/sdb1")
                         (mount-point "/gnu")
                         (type "ext4")
                         (needed-for-boot? #t))
                       %base-file-systems))
--8<---------------cut here---------------end--------------->8---

When rebooting the installed system, I have to edit GRUB command line
(pressing 'e'), which was:

--8<---------------cut here---------------start------------->8---
  search --file --set /gnu/store/2qh58nr4sxc5jwv2ng9sqq06niab8sjp-linux-libre-4.7/bzImage
  linux /gnu/store/2qh58nr4sxc5jwv2ng9sqq06niab8sjp-linux-libre-4.7/bzImage --root=my-root --system=/gnu/store/4ji3d5v5ci91l69fgi4hdi73kc558whp-system --load=/gnu/store/4ji3d5v5ci91l69fgi4hdi73kc558whp-system/boot
  initrd /gnu/store/4ji3d5v5ci91l69fgi4hdi73kc558whp-system/initrd
--8<---------------cut here---------------end--------------->8---

By:

1) removing "/gnu" from search command, so GRUB root (not kernel root)
   is correctly set as (hd1,msdos1), i.e. /dev/sdb1
2) removing "/gnu" from linux command, so the kernel is correctly loaded
   by GRUB (/gnu is not removed from --system or --load, as those
   commands are interpreted by gnu/build/linux-boot.scm after all
   needed-for-boot filesystems have been mounted in their correct mount
   points).
3) changing initrd path. Removing "/gnu" is not enough, as the path in
   grub.cfg is a symlink to the real initrd, pointing into /gnu/store
   which is not available at initrd-loading time. So I placed the
   synlink destination there, removing "/gnu", so:

initrd /store/<hash>-base-initrd/initrd

And voilá, I can boot into my newly installed GuixSD with /gnu/store in
a separate partition.

Some other files (modules, background image) fail to be accesses by GRUB
as well with generated grub.cfg, but those are not essential to make the
system boot, in my system at least.

BR

Carlos

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-08-31 12:48     ` Carlos Sánchez de La Lama
@ 2016-08-31 21:21       ` Ludovic Courtès
  2016-09-01  4:34         ` John Darrington
  0 siblings, 1 reply; 11+ messages in thread
From: Ludovic Courtès @ 2016-08-31 21:21 UTC (permalink / raw)
  To: Carlos Sánchez de La Lama; +Cc: guix-devel, Alex Kost, bug-guix

Hi,

csanchezdll@gmail.com (Carlos Sánchez de La Lama) skribis:

> When rebooting the installed system, I have to edit GRUB command line
> (pressing 'e'), which was:
>
>   search --file --set /gnu/store/2qh58nr4sxc5jwv2ng9sqq06niab8sjp-linux-libre-4.7/bzImage
>   linux /gnu/store/2qh58nr4sxc5jwv2ng9sqq06niab8sjp-linux-libre-4.7/bzImage --root=my-root --system=/gnu/store/4ji3d5v5ci91l69fgi4hdi73kc558whp-system --load=/gnu/store/4ji3d5v5ci91l69fgi4hdi73kc558whp-system/boot
>   initrd /gnu/store/4ji3d5v5ci91l69fgi4hdi73kc558whp-system/initrd
>
> By:
>
> 1) removing "/gnu" from search command, so GRUB root (not kernel root)
>    is correctly set as (hd1,msdos1), i.e. /dev/sdb1
> 2) removing "/gnu" from linux command, so the kernel is correctly loaded
>    by GRUB (/gnu is not removed from --system or --load, as those
>    commands are interpreted by gnu/build/linux-boot.scm after all
>    needed-for-boot filesystems have been mounted in their correct mount
>    points).
> 3) changing initrd path. Removing "/gnu" is not enough, as the path in
>    grub.cfg is a symlink to the real initrd, pointing into /gnu/store
>    which is not available at initrd-loading time. So I placed the
>    synlink destination there, removing "/gnu", so:
>
> initrd /store/<hash>-base-initrd/initrd
>
> And voilá, I can boot into my newly installed GuixSD with /gnu/store in
> a separate partition.

Ooh, I see.

We should fix our grub.cfg generation to take this into account
somehow.  I’ve reported filed it to bug-guix@gnu.org:

  http://debbugs.gnu.org/cgi/bugreport.cgi?bug=24346

Please email 24346@debbugs.gnu.org if you have suggestions on how to
fix it.

Thanks!

Ludo’.

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-08-31 21:21       ` Ludovic Courtès
@ 2016-09-01  4:34         ` John Darrington
  2016-09-01  6:35           ` Vincent Legoll
  0 siblings, 1 reply; 11+ messages in thread
From: John Darrington @ 2016-09-01  4:34 UTC (permalink / raw)
  To: Ludovic Court??s; +Cc: guix-devel, Alex Kost, bug-guix

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On Wed, Aug 31, 2016 at 11:21:32PM +0200, Ludovic Court??s wrote:

     > And voil??, I can boot into my newly installed GuixSD with /gnu/store in
     > a separate partition.

That's great.

It would be wonderful if we could go one step further, and have source derivations on
a separate partition to binary derivations.  Those two kinds of object have significantly,
different access patterns, and would benefit from being stored on different media.

J'
     

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^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: Store on separate partition
  2016-09-01  4:34         ` John Darrington
@ 2016-09-01  6:35           ` Vincent Legoll
  0 siblings, 0 replies; 11+ messages in thread
From: Vincent Legoll @ 2016-09-01  6:35 UTC (permalink / raw)
  To: John Darrington; +Cc: guix-devel, bug-guix, Alex Kost

Hello,

> It would be wonderful if we could go one step further, and have source derivations on
> a separate partition to binary derivations.  Those two kinds of object have significantly,
> different access patterns, and would benefit from being stored on different media.

+1

and then it would be cool to split guix-daemon's --gc-keep-derivations into
--gc-keep-source-derivations & --gc-keep-binary-derivations...

-- 
Vincent Legoll

^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2016-09-01  6:35 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-08-24  7:06 Store on separate partition Carlos Sánchez de La Lama
2016-08-24  7:35 ` Vincent Legoll
2016-08-24  8:18 ` Alex Kost
2016-08-24 10:37   ` Carlos Sánchez de La Lama
2016-08-25 14:30     ` Tomáš Čech
2016-08-25 22:04       ` Tomáš Čech
2016-08-29 16:15   ` Ludovic Courtès
2016-08-31 12:48     ` Carlos Sánchez de La Lama
2016-08-31 21:21       ` Ludovic Courtès
2016-09-01  4:34         ` John Darrington
2016-09-01  6:35           ` Vincent Legoll

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