Because I am avoiding "single partition per directory". And a slight
mistake in my original email, it's not just /usr but also /var (and
other root-based directories that will not interfere with boot-up /
operations)
Let me give an example:
Let's say I have /dev/sdc and /dev/sdd, both having single partition
each (/dev/sdc1 and /dev/sdd1).
/dev/sdc1 will be formatted reiserfs mounted into /mnt/Persistent1
/dev/sdd1 will be formatted ext4 mounted into /mnt/Persistent2
Directories not really necessary for daily operations, such as
/usr/src, /usr/portage, /var/db/pkg, and so on and so forth, will each
be a subdir under either /mnt/Persistent1 or /mnt/Persistent2
according to each directory's nature.
Let's take the example of /usr/src ... I can either make /usr/src a
symlink to /mnt/Persistent1/src, or bindmount /mnt/Persistent1/src to
/usr/src
What will be the benefits/drawbacks for bindmount vs symlink?
Rgds,
--
FdS Pandu E Poluan
~ IT Optimizer ~
Â*• LOPSA Member #15248
Â*• Blog : http://pepoluan.tumblr.com
Â*• Linked-In : http://id.linkedin.com/in/pepoluan
03-13-2012, 04:45 AM
Canek Peláez Valdés
bindmount or symlink?
On Mon, Mar 12, 2012 at 11:39 PM, Pandu Poluan <pandu@poluan.info> wrote:
> On Tue, Mar 13, 2012 at 12:11, Canek Peláez Valdés <caneko@gmail.com> wrote:
>> On Mon, Mar 12, 2012 at 11:04 PM, Pandu Poluan <pandu@poluan.info> wrote:
>>> I am seriously thinking of splitting the storage of directories under /usr,
>>> e.g., /usr/portage and /usr/source actually living somewhere else, on
>>> different partition and different filesystem. Let's say something mounted on
>>> /mnt/Persistent.
>>>
>>> My question: should I use bindmount or symlinks to do that? What's the
>>> drawbacks/benefits for either?
>>
>> I'm sorry, I don't understand. What's the problem of having the
>> following in /etc/fstab?
>>
>> LABEL=Portage * /usr/portage * * * * * *ext4 * * * * * *noatime,auto * * * * * * * * * *0 2
>> LABEL=Source * * * * * */usr/source * * * * * * ext4 * * * * * *noatime,auto * * * * * * * * * *0 2
>>
>> (Replace LABEL=Portage with /dev/sda7, if you want to.)
>>
>> Why do you need to bindmount or link the directories when you can
>> mount them wherever you want?
>>
>
> Because I am avoiding "single partition per directory". And a slight
> mistake in my original email, it's not just /usr but also /var (and
> other root-based directories that will not interfere with boot-up /
> operations)
>
> Let me give an example:
>
> Let's say I have /dev/sdc and /dev/sdd, both having single partition
> each (/dev/sdc1 and /dev/sdd1).
>
> /dev/sdc1 will be formatted reiserfs mounted into /mnt/Persistent1
>
> /dev/sdd1 will be formatted ext4 mounted into /mnt/Persistent2
>
> Directories not really necessary for daily operations, such as
> /usr/src, /usr/portage, /var/db/pkg, and so on and so forth, will each
> be a subdir under either /mnt/Persistent1 or /mnt/Persistent2
> according to each directory's nature.
>
> Let's take the example of /usr/src ... I can either make /usr/src a
> symlink to /mnt/Persistent1/src, or bindmount /mnt/Persistent1/src to
> /usr/src
All of that sounds incredible complicated. Interesting choice of
partition handling.
> What will be the benefits/drawbacks for bindmount vs symlink?
In my experience, and if you are not dealing with NFS, no respectable
program cares about a dir being a symlink, so I would use symlinks
(they are easier to handle).
Regards.
--
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México
03-13-2012, 05:59 AM
Alan McKinnon
bindmount or symlink?
On Tue, 13 Mar 2012 12:04:00 +0700
Pandu Poluan <pandu@poluan.info> wrote:
> I am seriously thinking of splitting the storage of directories
> under /usr, e.g., /usr/portage and /usr/source actually living
> somewhere else, on different partition and different filesystem.
> Let's say something mounted on /mnt/Persistent.
>
> My question: should I use bindmount or symlinks to do that? What's the
> drawbacks/benefits for either?
>
> Rgds,
You should do neither as they do not give you split storage, they
both give you the same thing in two different places.
Create two new filesystems and mount them.
I personally use /var/portage as there is no good reason for it to be
under /usr where it is just clutter.
Code goes in /usr
Data goes in /var
You have to change PORTDIR in /etc/make.conf for this to work as well
as /etc/make.profile. Nothing breaks without it, you just get errors
from portage
--
Alan McKinnnon
alan.mckinnon@gmail.com
03-13-2012, 07:05 AM
Pandu Poluan
bindmount or symlink?
On Mar 13, 2012 2:00 PM, "Alan McKinnon" <alan.mckinnon@gmail.com> wrote:
>
> On Tue, 13 Mar 2012 12:04:00 +0700
> Pandu Poluan <pandu@poluan.info> wrote:
>
> > I am seriously thinking of splitting the storage of directories
> > under /usr, e.g., /usr/portage and /usr/source actually living
> > somewhere else, on different partition and different filesystem.
> > Let's say something mounted on /mnt/Persistent.
> >
> > My question: should I use bindmount or symlinks to do that? What's the
> > drawbacks/benefits for either?
> >
> > Rgds,
>
> You should do neither as they do not give you split storage, they
> both give you the same thing in two different places.
>
> Create two new filesystems and mount them.
>
> I personally use /var/portage as there is no good reason for it to be
> under /usr where it is just clutter.
>
> Code goes in /usr
> Data goes in /var
>
> You have to change PORTDIR in /etc/make.conf for this to work as well
> as /etc/make.profile. Nothing breaks without it, you just get errors
> from portage
>
Eh? But I put portage, src, share, etc. on a different partition mounted under /mnt ... doesn't that mean I am using a split filesystem?
Rgds,
03-13-2012, 07:15 AM
Canek Peláez Valdés
bindmount or symlink?
On Tue, Mar 13, 2012 at 2:05 AM, Pandu Poluan <pandu@poluan.info> wrote:
>
> On Mar 13, 2012 2:00 PM, "Alan McKinnon" <alan.mckinnon@gmail.com> wrote:
>>
>> On Tue, 13 Mar 2012 12:04:00 +0700
>> Pandu Poluan <pandu@poluan.info> wrote:
>>
>> > I am seriously thinking of splitting the storage of directories
>> > under /usr, e.g., /usr/portage and /usr/source actually living
>> > somewhere else, on different partition and different filesystem.
>> > Let's say something mounted on /mnt/Persistent.
>> >
>> > My question: should I use bindmount or symlinks to do that? What's the
>> > drawbacks/benefits for either?
>> >
>> > Rgds,
>>
>> You should do neither as they do not give you split storage, they
>> both give you the same thing in two different places.
>>
>> Create two new filesystems and mount them.
>>
>> I personally use /var/portage as there is no good reason for it to be
>> under /usr where it is just clutter.
>>
>> Code goes in /usr
>> Data goes in /var
>>
>> You have to change PORTDIR in /etc/make.conf for this to work as well
>> as /etc/make.profile. Nothing breaks without it, you just get errors
>> from portage
>>
>
> Eh? But I put portage, src, share, etc. on a different partition mounted
> under /mnt ... doesn't that mean I am using a split filesystem?
You are; but in an incredible complicated and convulted way.
If I'm understanding you, you want:
fstab:
/dev/XX /mnt/p1 ...
/dev/YY /mnt/p2 ...
and then
/usr/portage -> /mnt/p1
/usr/src -> /mnt/p2
(or using bindmounting, whatever).
This makes no sense at all (at least not to me), when you can simply:
and get the same split filesystem, but without all the complication
you are proposing.
Unless there is something I don't understand, in which case I'm not
following your reasoning.
There are 2 possible things one can do:
1) Split everything, /usr, /usr/src, /usr/portage each on a seperate
filesystem.
2) Seperate multiple paths from /usr: Have 1 fs /mnt/data and link (or
bind mount) /usr/src, /usr/portage there. You have a shared fs for dirx,
that are usually not shared.
What would be the benefits of symlinks and bind mounts for doing 2)?
The point is: It's not just 2 (two) directories, but several of them,
and I just can't see myself creating a partition (or an LV) for each
and everyone of them.
So, here's my thoughts:
There are 2 filesystems that are suitable for different purposes:
* reiserfs = for space efficiency (w/o notail option) and/or no inode#
limitation
* ext4 = for general purpose
Finally, I need to redirect the directories-I-want-to-split to the
above subdirs under /mnt/Persistent[12]
SO.
mount -o bind ... or ln -s ?
Rgds,
--
FdS Pandu E Poluan
~ IT Optimizer ~
Â*• LOPSA Member #15248
Â*• Blog : http://pepoluan.tumblr.com
Â*• Linked-In : http://id.linkedin.com/in/pepoluan
03-13-2012, 08:12 AM
Canek Peláez Valdés
bindmount or symlink?
On Tue, Mar 13, 2012 at 3:00 AM, Pandu Poluan <pandu@poluan.info> wrote:
> On Tue, Mar 13, 2012 at 15:15, Canek Peláez Valdés <caneko@gmail.com> wrote:
>>
>> You are; but in an incredible complicated and convulted way.
>>
>> If I'm understanding you, you want:
>>
>> fstab:
>> /dev/XX * /mnt/p1 * ...
>> /dev/YY * /mnt/p2 * ...
>>
>> and then
>>
>> /usr/portage -> /mnt/p1
>> /usr/src -> /mnt/p2
>>
>> (or using bindmounting, whatever).
>>
>> This makes no sense at all (at least not to me), when you can simply:
>>
>> fstab:
>> /dev/XX * /usr/portage * ...
>> /dev/YY * /usr/src * ...
>>
>> and get the same split filesystem, but without all the complication
>> you are proposing.
>>
>> Unless there is something I don't understand, in which case I'm not
>> following your reasoning.
>>
>
> The point is: It's not just 2 (two) directories, but several of them,
> and I just can't see myself creating a partition (or an LV) for each
> and everyone of them.
>
> So, here's my thoughts:
>
> There are 2 filesystems that are suitable for different purposes:
> * reiserfs = for space efficiency (w/o notail option) and/or no inode#
> limitation
> * ext4 = for general purpose
>
> The directories I'm going to split:
>
> /usr/share ==> ext4
> /usr/portage ==> reiserfs
> /usr/portage/packages ==> ext4
> /usr/portage/distfiles ==> ext4
> /usr/src ==> reiserfs
> /var/cache/rtorrent (don't ask) ==> reiserfs
> /var/spool/postfix ==> ext4
> /var/lib/postgresql ==> ext4
>
> Now, I create 2 partitions:
>
> /dev/sdc1 (reiserfs) --> /mnt/Persistent1
> /dev/sdd1 (ext4) --> /mnt/Persistent2
>
> Then I create subdirectories:
>
> /mnt/Persistent1/portage
> /mnt/Persistent1/src
> /mnt/Persistent1/rtorrent
>
> /mnt/Persistent2/share
> /mnt/Persistent2/packages
> /mnt/Persistent2/distfiles
> /mnt/Persistent2/postfix
> /mnt/Persistent2/postgresql
>
> Finally, I need to redirect the directories-I-want-to-split to the
> above subdirs under /mnt/Persistent[12]
>
> SO.
>
> mount -o bind ... or ln -s ?
OK, now I understand. I still think is kinda crazy, but to each its own.
I would definitely use symlinks.
Regards.
--
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México
03-13-2012, 09:35 AM
Nilesh Govindrajan
bindmount or symlink?
On Mar 13, 2012 2:42 PM, "Canek Peláez Valdés" <caneko@gmail.com> wrote:
>
> On Tue, Mar 13, 2012 at 3:00 AM, Pandu Poluan <pandu@poluan.info> wrote:
> > On Tue, Mar 13, 2012 at 15:15, Canek Peláez Valdés <caneko@gmail.com> wrote:
> >>
> >> You are; but in an incredible complicated and convulted way.
> >>
> >> If I'm understanding you, you want:
> >>
> >> fstab:
> >> /dev/XX * /mnt/p1 * ...
> >> /dev/YY * /mnt/p2 * ...
> >>
> >> and then
> >>
> >> /usr/portage -> /mnt/p1
> >> /usr/src -> /mnt/p2
> >>
> >> (or using bindmounting, whatever).
> >>
> >> This makes no sense at all (at least not to me), when you can simply:
> >>
> >> fstab:
> >> /dev/XX * /usr/portage * ...
> >> /dev/YY * /usr/src * ...
> >>
> >> and get the same split filesystem, but without all the complication
> >> you are proposing.
> >>
> >> Unless there is something I don't understand, in which case I'm not
> >> following your reasoning.
> >>
> >
> > The point is: It's not just 2 (two) directories, but several of them,
> > and I just can't see myself creating a partition (or an LV) for each
> > and everyone of them.
> >
> > So, here's my thoughts:
> >
> > There are 2 filesystems that are suitable for different purposes:
> > * reiserfs = for space efficiency (w/o notail option) and/or no inode#
> > limitation
> > * ext4 = for general purpose
> >
> > The directories I'm going to split:
> >
> > /usr/share ==> ext4
> > /usr/portage ==> reiserfs
> > /usr/portage/packages ==> ext4
> > /usr/portage/distfiles ==> ext4
> > /usr/src ="" reiserfs
> > /var/cache/rtorrent (don't ask) ==> reiserfs
> > /var/spool/postfix ==> ext4
> > /var/lib/postgresql ==> ext4
> >
> > Now, I create 2 partitions:
> >
> > /dev/sdc1 (reiserfs) --> /mnt/Persistent1
> > /dev/sdd1 (ext4) --> /mnt/Persistent2
> >
> > Then I create subdirectories:
> >
> > /mnt/Persistent1/portage
> > /mnt/Persistent1/src
> > /mnt/Persistent1/rtorrent
> >
> > /mnt/Persistent2/share
> > /mnt/Persistent2/packages
> > /mnt/Persistent2/distfiles
> > /mnt/Persistent2/postfix
> > /mnt/Persistent2/postgresql
> >
> > Finally, I need to redirect the directories-I-want-to-split to the
> > above subdirs under /mnt/Persistent[12]
> >
> > SO.
> >
> > mount -o bind ... or ln -s ?
>
> OK, now I understand. I still think is kinda crazy, but to each its own.
>
> I would definitely use symlinks.
>
> Regards.
> --
> Canek Peláez Valdés
> Posgrado en Ciencia e Ingeniería de la Computación
> Universidad Nacional Autónoma de México
>
For critically performance wise, I think bindmounts would do better because it is done at kernel level whereas symlinks will have to be resolved on access, no dobut a kernel maintains cache but I can't really say much about it because I don't know the code behind either.
--
Nilesh Govindrajan
http://nileshgr.com
03-13-2012, 09:58 AM
Alan McKinnon
bindmount or symlink?
On Tue, 13 Mar 2012 15:05:59 +0700
Pandu Poluan <pandu@poluan.info> wrote:
> On Mar 13, 2012 2:00 PM, "Alan McKinnon" <alan.mckinnon@gmail.com>
> wrote:
> >
> > On Tue, 13 Mar 2012 12:04:00 +0700
> > Pandu Poluan <pandu@poluan.info> wrote:
> >
> > > I am seriously thinking of splitting the storage of directories
> > > under /usr, e.g., /usr/portage and /usr/source actually living
> > > somewhere else, on different partition and different filesystem.
> > > Let's say something mounted on /mnt/Persistent.
> > >
> > > My question: should I use bindmount or symlinks to do that?
> > > What's the drawbacks/benefits for either?
> > >
> > > Rgds,
> >
> > You should do neither as they do not give you split storage, they
> > both give you the same thing in two different places.
> >
> > Create two new filesystems and mount them.
> >
> > I personally use /var/portage as there is no good reason for it to
> > be under /usr where it is just clutter.
> >
> > Code goes in /usr
> > Data goes in /var
> >
> > You have to change PORTDIR in /etc/make.conf for this to work as
> > well as /etc/make.profile. Nothing breaks without it, you just get
> > errors from portage
> >
>
> Eh? But I put portage, src, share, etc. on a different partition
> mounted under /mnt ... doesn't that mean I am using a split
> filesystem?
Do you have separate filesystems for each of those directories, or one
big storage area? I'm struggling to find out what you are trying to
accomplish and what problem that is a solution for.
bindmount or symlink?
