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authorThomas Schwinge <tschwinge@gnu.org>2012-08-07 23:25:26 +0200
committerThomas Schwinge <tschwinge@gnu.org>2012-08-07 23:25:26 +0200
commit2603401fa1f899a8ff60ec6a134d5bd511073a9d (patch)
treeccac6e11638ddeee8da94055b53f4fdfde73aa5c /hurd/subhurd/discussion.mdwn
parentd72694b33a81919368365da2c35d5b4a264648e0 (diff)
IRC.
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@@ -1,4 +1,4 @@
-[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
+[[!meta copyright="Copyright © 2011, 2012 Free Software Foundation, Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
id="license" text="Permission is granted to copy, distribute and/or modify this
@@ -8,9 +8,10 @@ Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license
is included in the section entitled [[GNU Free Documentation
License|/fdl]]."]]"""]]
-[[!tag open_issue_documentation]]
+[[!tag open_issue_documentation open_issue_hurd]]
-IRC, freenode, #hurd, 2011-08-10
+
+# IRC, freenode, #hurd, 2011-08-10
< braunr> youpi: aren't sub-hurds actually called "neighbor hurds" ?
< youpi> no idea
@@ -67,3 +68,92 @@ IRC, freenode, #hurd, 2011-08-10
< antrik> I don't think that's actually supported in the boot
program... but it doesn't really matter, as you don't really need the
terminal anyways -- you can always log in through the network
+
+
+# IRC, freenode, #hurd, 2012-07-31
+
+ <gg0> subhurd seems like bsd jail (tried none of them)
+ <antrik> gg0: nope. BSD jails are mostly chroot AIUI. subhurd is quite
+ different
+ <antrik> gg0: you actually boot a completely new system instance
+ <antrik> complete with all the Hurd servers, UNIX daemons etc.
+ <braunr> jails are between subhhurds and chroots :p
+ <braunr> i suppose there is nothing against making the root server of the
+ subhurd use a file instead of a raw disk, is there ?
+ <gg0> well, I said jails cos afaik are more isolated from real system than
+ chroots
+ <braunr> yes
+ <gg0> maybe comparing subhurd to virtual machines would be more
+ appropriated then
+ <braunr> they're not VMs either
+ <gg0> say chroot -> jail -> subhurd -> vm ?
+ <braunr> unless you consider the microkernel to be a hypervisor, with its
+ own architecture, which some actually do
+ <braunr> gg0: something like that, yes
+ <gg0> [system-in-system evolution]
+ <braunr> a subhurd is an operating system instance
+ <braunr> i think the closest analogy you can get is openvz
+ <antrik> yeah, I'd also consider it closest. but it's still quite
+ different: with OpenVZ, the kernel facilities are only logically
+ isolated; but they use the same kernel code. with subhurds, most of the
+ system facilities are independent
+
+
+# IRC, freenode, #hurd, 2012-08-03
+
+ <antrik> hm... are Mach task IDs exposed to userspace?
+ <braunr> antrik: ids ?
+ <braunr> antrik: what do you call a mach task id ?
+ <antrik> task have numeric IDs in the kernel
+ <antrik> I wonder whether these are ever exposed to userspace
+ <braunr> i'm not sure
+ <braunr> i don't remember the had numeric IDs
+ <braunr> they*
+ <antrik> well, perhaps I'm making things up... but I believe I saw such IDs
+ in the debugger and/or in error messages
+ <braunr> probably their address
+ <braunr> or creation time orpc_sample
+ <antrik> braunr: well, any unique ID would do
+ <braunr> antrik: yes but i was wondering what kdb would actually show
+ <antrik> I just realised that it would be useful for debugging accross
+ subhurds or kernel/userspace if some kind of unique task IDs could be
+ shown in ps output
+ <braunr> yes
+ <braunr> this requires some thought though
+ <braunr> ps shouldn't show that
+ <braunr> there should be mach specific commands i suppose
+ <braunr> but then, gdb and other tools wouldn't have access to subhurd
+ tasks either
+ <antrik> why shouldn't ps show that? I don't think it's any more sensitive
+ information than all the other stuff ps shows...
+ <braunr> it doesn't feel right
+ <braunr> i would want my system instances to be truely isolated
+ <braunr> and use special "cross instance" facilities
+ <braunr> when necessary
+ <antrik> that's completely orthogonal to what I'm talking about
+ <braunr> like eth-multiplexer
+ <braunr> you seem to be talking about security
+ <braunr> or privacy
+ <antrik> we discussed such options when zhengda worked on rootless subhurd
+ <antrik> no, I'm talking about convenient debugging
+ <braunr> right
+ <braunr> i don't think it'zs orthogonal here
+ <braunr> if we increase separation, it becomes less convenient
+ <antrik> for debugging purposes you would *not* use the isolation options
+ <braunr> ok so you propose two modes of operations
+ <antrik> BTW, as an isolated subhurd relies on the parent, it makes no
+ sense to hide subhurd tasks from the parent hurd -- only hide parent hurd
+ task from the subhurd
+ <braunr> agreed
+ <antrik> so even with an isolated subhurd global task IDs would still be
+ useful
+
+
+# IRC, freenode, #hurd, 2012-08-06
+
+ <braunr> antrik: if i'm right, the root file system executable is read from
+ the parent, right ?
+ <antrik> braunr: probably... I'm not sure about that part
+ <braunr> antrik: i've installed the same packages in both the main and
+ subhurds to be sure
+ <braunr> and to have the right binary and debugging symbols in gdb anyway