Re: [gentoo-dev] supporting /usr on separate partition
Splitting this up since i'm kind of starting two threads here.. - Documentation discussion - On 16/10/11 02:44 PM, Zac Medico wrote: Well, you'll have to define the meaning of support in this context. I simply said that it shouldn't be encouraged, with me reason being that it tends to add unnecessary complexity (in violation of the KISS principle [1]). I would agree with this (that it shouldn't be encouraged), but I don't think the Handbook is encouraging it now, as it is written.. As per the documentation itself, Code Listing 2.1 is i believe an example of what is possible, not what we are encouraging users to do. That doc seems pretty clear that the default is partitioning scheme is the default /boot,/,swap ... Why should our main installation docs mention a configuration that the vast majority of our users (all?) would be better off without? You'd have to talk to the original authors to confirm but I believe this would be to illustrate the possibilities and give users info that will let them think about their partitioning scheme, instead of telling them what to do. Essentially, to introduce and educate about partitions and filesystems. (it is the Gentoo Handbook, not the Gentoo Quick Install Howto, after all) What's the benefit of having /usr on a separate partition anyway? I think that's covered rather generically in the guide -- different fs type, won't run out of space on / if /usr fills up, different mount options (ie, mounting ROOT ro and /usr rw); and of course if /usr is on separate physical media (ie, a nice big RAID, while / is on, say, a small SSD). - Support/implementation discussion - ... If people want that, I think it's perfectly reasonable to expect them to use either an initramfs or a simple linuxrc approach [2] to ensure that /usr is mounted before init starts. ...this would make sense, although in terms of support i think it would be appropriate that we would provide this linuxrc wrapper on any init system that needs /usr mounted.
Re: [gentoo-dev] supporting /usr on separate partition
On 10/17/2011 09:02 AM, Ian Stakenvicius wrote: Splitting this up since i'm kind of starting two threads here.. - Documentation discussion - On 16/10/11 02:44 PM, Zac Medico wrote: Well, you'll have to define the meaning of support in this context. I simply said that it shouldn't be encouraged, with me reason being that it tends to add unnecessary complexity (in violation of the KISS principle [1]). I would agree with this (that it shouldn't be encouraged), but I don't think the Handbook is encouraging it now, as it is written.. It depends on how you define encouraging in this context. The fact that /usr is shown as a separate partition might be considered suggestive if not encouraging. If a user takes that suggestion without knowing the consequences (special initramfs or linuxrc init wrapper configuration), then then it could cause some disappointment when they finally discover the consequences. - Support/implementation discussion - ... If people want that, I think it's perfectly reasonable to expect them to use either an initramfs or a simple linuxrc approach [2] to ensure that /usr is mounted before init starts. ...this would make sense, although in terms of support i think it would be appropriate that we would provide this linuxrc wrapper on any init system that needs /usr mounted. If someone wants to take on the burden of maintaining an init wrapper like that, then I guess that's fine. However, I wouldn't consider it to be an absolute requirement. I think it would be fine (maybe preferable) to simply provide a doc that describes how to mount /usr via an initramfs or linuxrc init wrapper. Such a doc would only be needed by those users who require that /usr be on a separate partition. -- Thanks, Zac
Re: [gentoo-dev] supporting /usr on separate partition
...and recombining again.. On 2011-10-17, at 1:24 PM, Zac Medico zmed...@gentoo.org wrote: On 10/17/2011 09:02 AM, Ian Stakenvicius wrote: Splitting this up since i'm kind of starting two threads here.. - Documentation discussion - On 16/10/11 02:44 PM, Zac Medico wrote: Well, you'll have to define the meaning of support in this context. I simply said that it shouldn't be encouraged, with me reason being that it tends to add unnecessary complexity (in violation of the KISS principle [1]). I would agree with this (that it shouldn't be encouraged), but I don't think the Handbook is encouraging it now, as it is written.. It depends on how you define encouraging in this context. The fact that /usr is shown as a separate partition might be considered suggestive if not encouraging. If a user takes that suggestion without knowing the consequences (special initramfs or linuxrc init wrapper configuration), then then it could cause some disappointment when they finally discover the consequences. - Support/implementation discussion - ... If people want that, I think it's perfectly reasonable to expect them to use either an initramfs or a simple linuxrc approach [2] to ensure that /usr is mounted before init starts. ...this would make sense, although in terms of support i think it would be appropriate that we would provide this linuxrc wrapper on any init system that needs /usr mounted. If someone wants to take on the burden of maintaining an init wrapper like that, then I guess that's fine. However, I wouldn't consider it to be an absolute requirement. I think it would be fine (maybe preferable) to simply provide a doc that describes how to mount /usr via an initramfs or linuxrc init wrapper. Such a doc would only be needed by those users who require that /usr be on a separate partition. This makes sense. So the Handbook could be updated with a caveat after the large partition example to say something like /usr on it's own partition needs special consideration, please see X ... this works.
Re: [gentoo-dev] supporting /usr on separate partition
On 10/17/2011 08:50 PM, Ian Stakenvicius wrote: please disable HTML in your mail client.
Re: [gentoo-dev] supporting /usr on separate partition
On 17/10/11 01:55 PM, Samuli Suominen wrote: On 10/17/2011 08:50 PM, Ian Stakenvicius wrote: please disable HTML in your mail client. CRAP. sorry all. will stop emailing from my phone.
Re: [gentoo-dev] supporting /usr on separate partition
On Mon, Oct 17, 2011 at 01:50:04PM -0400, Ian Stakenvicius wrote: If someone wants to take on the burden of maintaining an init wrapper like that, then I guess that's fine. However, I wouldn't consider it to be an absolute requirement. I think it would be fine (maybe preferable) to simply provide a doc that describes how to mount /usr via an initramfs or linuxrc init wrapper. Such a doc would only be needed by those users who require that /usr be on a separate partition. This makes sense. So the Handbook could be updated with a caveat after the large partition example to say something like /usr on it's own partition needs special consideration, please see X ... this$ works. (Ian, it's a general reply, not specific to your e-mail) I've updated the Gentoo Handbook just a few moments ago to mention something like this in the introduction of the partition section How Many and How Big: --Snippet from the commit result: p However, multiple partitions have disadvantages as well. If not configured properly, you will have a system with lots of free space on one partition and none on another. Another nuisance is that separate partitions - especially for important mountpoints like path/usr/path or path/var/path - often require the administrator to boot with an initramfs to mount the partition before other boot scripts start. This isn't always the case though, so YMMV. /p p There is also a 15-partition limit for SCSI and SATA unless you use GPT labels. /p --End Snippet Now, I must say I find it strange that people think that the Gentoo Handbook suggests users to use a separate /usr partition. It does not. The default partitioning that we use is a separate /boot (yes, this can and has been debated in the past, I'm not going to change this) and / with a separate swap partition. Nothing more, nothing less. There are a few code listings where an example output is given which holds a separate /usr but I hope all those listings are clear that they are examples. It also states that this is an example we use in the Gentoo Handbook and that it depends on the user how he wants his partition scheme layed out. I'm hoping that the above update clarifies this sufficiently so that huge threads like this one don't need to reappear again ;-) If you think it is still unclear or needs improvements left or right, don't hesitate to mail me or, even better, file a bugreport (I act better on bug reports than on e-mails). Oh, and I use a separate /usr with no initramfs (yet), with software raid and lvm2. /me quickly hides Wkr, Sven Vermeulen
Re: [gentoo-dev] supporting /usr on separate partition
On 10/17/2011 01:01 PM, Sven Vermeulen wrote: --Snippet from the commit result: p However, multiple partitions have disadvantages as well. If not configured properly, you will have a system with lots of free space on one partition and none on another. Another nuisance is that separate partitions - especially for important mountpoints like path/usr/path or path/var/path - often require the administrator to boot with an initramfs to mount the partition before other boot scripts start. This isn't always the case though, so YMMV. /p p There is also a 15-partition limit for SCSI and SATA unless you use GPT labels. /p --End Snippet Now, I must say I find it strange that people think that the Gentoo Handbook suggests users to use a separate /usr partition. It does not. The default partitioning that we use is a separate /boot (yes, this can and has been debated in the past, I'm not going to change this) and / with a separate swap partition. Nothing more, nothing less. There are a few code listings where an example output is given which holds a separate /usr but I hope all those listings are clear that they are examples. Even if you don't consider them to be formal suggestions, their mere presence as examples lends them credence. It also states that this is an example we use in the Gentoo Handbook and that it depends on the user how he wants his partition scheme layed out. I'm hoping that the above update clarifies this sufficiently so that huge threads like this one don't need to reappear again ;-) If you think it is still unclear or needs improvements left or right, don't hesitate to mail me or, even better, file a bugreport (I act better on bug reports than on e-mails). I think the new disadvantages section that you posted should convey an appropriate level of caution. Thanks! -- Thanks, Zac
Re: [gentoo-dev] supporting /usr on separate partition (was: Suggestion for getting rid of udev)
On 15/10/11 06:07 PM, Zac Medico wrote: On 10/15/2011 01:57 AM, Wulf C. Krueger wrote: On 15.10.2011 10:42, Michael Schreckenbauer wrote: in what way will exherbo deal wih this mess? Are there any plans? We don't support /usr on a separate partition. People can, of course, do that and I'll point them to dracut for creating an initramfs. Or they can do whatever works for them. People using Exherbo are expected to be able to deal with such stuff. I don't think it's a good idea for Gentoo to encourage users to have /usr on a separate partition. We should probably remove the separate /usr partition from Code Listing 2.1: Filesystem usage example in our handbook: http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1chap=4#doc_chap2_pre1 For desktops i've never seen much purpose of having /usr on its own partition (or more than the usual 3 of /boot,/,swap tbh), but for servers I have seen a lot of configurations over the years that put /usr on its own partition. Exherbo aside, I would expect that Gentoo would (continue to?) support doing this. As per the documentation itself, Code Listing 2.1 is i believe an example of what is possible, not what we are encouraging users to do. That doc seems pretty clear that the default is partitioning scheme is the default /boot,/,swap ... And just to confirm, doesn't udev's installation (which is primarily in /lib) support /usr on a separate partition now, without an initramfs?
Re: [gentoo-dev] supporting /usr on separate partition
On 10/16/2011 05:52 AM, Ian Stakenvicius wrote: On 15/10/11 06:07 PM, Zac Medico wrote: On 10/15/2011 01:57 AM, Wulf C. Krueger wrote: On 15.10.2011 10:42, Michael Schreckenbauer wrote: in what way will exherbo deal wih this mess? Are there any plans? We don't support /usr on a separate partition. People can, of course, do that and I'll point them to dracut for creating an initramfs. Or they can do whatever works for them. People using Exherbo are expected to be able to deal with such stuff. I don't think it's a good idea for Gentoo to encourage users to have /usr on a separate partition. We should probably remove the separate /usr partition from Code Listing 2.1: Filesystem usage example in our handbook: http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=1chap=4#doc_chap2_pre1 For desktops i've never seen much purpose of having /usr on its own partition (or more than the usual 3 of /boot,/,swap tbh), but for servers I have seen a lot of configurations over the years that put /usr on its own partition. Exherbo aside, I would expect that Gentoo would (continue to?) support doing this. Well, you'll have to define the meaning of support in this context. I simply said that it shouldn't be encouraged, with me reason being that it tends to add unnecessary complexity (in violation of the KISS principle [1]). As per the documentation itself, Code Listing 2.1 is i believe an example of what is possible, not what we are encouraging users to do. That doc seems pretty clear that the default is partitioning scheme is the default /boot,/,swap ... Why should our main installation docs mention a configuration that the vast majority of our users (all?) would be better off without? And just to confirm, doesn't udev's installation (which is primarily in /lib) support /usr on a separate partition now, without an initramfs? What's the benefit of having /usr on a separate partition anyway? The only somewhat reasonable explanation that I've heard is so that it can be mounted readonly. If people want that, I think it's perfectly reasonable to expect them to use either an initramfs or a simple linuxrc approach [2] to ensure that /usr is mounted before init starts. For complex configurations like this, we can have a separate page of docs, like the raid+lvm2 page [3], and link it from the main installation docs if we want. [1] http://en.wikipedia.org/wiki/KISS_principle [2] http://archives.gentoo.org/gentoo-dev/msg_20749880f5bc5feda141488498729fe8.xml [3] http://www.gentoo.org/doc/en/gentoo-x86+raid+lvm2-quickinstall.xml -- Thanks, Zac
Re: [gentoo-dev] supporting /usr on separate partition
Zac Medico zmed...@gentoo.org writes: What's the benefit of having /usr on a separate partition anyway? The only somewhat reasonable explanation that I've heard is so that it can be mounted readonly. One benefit, especially in a large server 'farm' is that several servers can share the same /usr by NFS mounting, read-only, the same partition on all of the servers. This both ensures that all the servers are kept in-step and greatly simplifies the upgrade process.
Re: [gentoo-dev] supporting /usr on separate partition
On Sun, 16 Oct 2011 20:36:23 +0100 Graham Murray gra...@gmurray.org.uk wrote: Zac Medico zmed...@gentoo.org writes: What's the benefit of having /usr on a separate partition anyway? The only somewhat reasonable explanation that I've heard is so that it can be mounted readonly. One benefit, especially in a large server 'farm' is that several servers can share the same /usr by NFS mounting, read-only, the same partition on all of the servers. This both ensures that all the servers are kept in-step and greatly simplifies the upgrade process. Unless upgrade involves files being outside of /usr. -- Best regards, Michał Górny signature.asc Description: PGP signature
