1 |
Hi Canek - good to hear from you. |
2 |
|
3 |
On Sun, Mar 2, 2014 at 9:45 AM, Canek Peláez Valdés <caneko@×××××.com> wrote: |
4 |
> On Sun, Mar 2, 2014 at 10:57 AM, Mark Knecht <markknecht@×××××.com> wrote: |
5 |
>> Hi all, |
6 |
>> I'd like to check in and get some education concerning future |
7 |
>> configuration of my Gentoo machines. Thanks in advance. |
8 |
>> |
9 |
>> In the last few days there is a news announcement about needing to |
10 |
>> change kernel my configuration to enable CONFIG_FHANDLE to support |
11 |
>> udev-210. I'm currently at udev-208 and virtual/udev-208-r1 so no big |
12 |
>> deal yet. However reading the news announcement it appears this has |
13 |
>> more to do with systemd than anything else and I don't use systemd so |
14 |
>> does/will this effect my machines? |
15 |
> |
16 |
> Yes, it will; udev (independently of systemd) is using FHANDLE to find |
17 |
> the devices in the computer. |
18 |
> |
19 |
> udev is part of systemd, but it can be used separately. This is |
20 |
> supported by upstream (i.e., systemd). The change in the kernel config |
21 |
> is needed by udev. |
22 |
> |
23 |
|
24 |
So as an end user type I'm a little confused by this part of your |
25 |
response. When you say udev is 'part of systemd' do you mean at the |
26 |
project level? That's what I understand from your longer response |
27 |
below. |
28 |
|
29 |
>> NOTE: I have no problem I know about today enabling CONFIG_FHANDLE |
30 |
>> if it's recommended. |
31 |
> |
32 |
> It is: udev will not work without it. Even more: eudev (when they |
33 |
> catch up) will not work without it either, since eudev does no |
34 |
> original work; they just exorcise systemd from udev. |
35 |
> |
36 |
|
37 |
Good to know and I've already read a little more about it and enabled |
38 |
it in my kernel. |
39 |
|
40 |
>> That said there's an interesting (if it is to be believed) little |
41 |
>> rant thread over the last couple of days on LKML about Debian |
42 |
>> leadership forcing people into systemd. |
43 |
> |
44 |
> The Debian Technical Committee took the technical decision of using |
45 |
> systemd as default init system. There is no "forcing" here; Debian is |
46 |
> ruled by a Constitution, and they (very slowly) followed their rules |
47 |
> and laws to reach that decision. |
48 |
> |
49 |
>> I think the Gentoo devs forked |
50 |
>> udev to make either mdev or eudev but when it was announced it was too |
51 |
>> new for me so I just let it go by. |
52 |
> |
53 |
> Gentoo, by default, uses udev without systemd. Again, this is |
54 |
> supported by upstream (i.e., systemd), nothing special about it. |
55 |
> *Some* Gentoo developers "forked" systemd into eudev, so you can have |
56 |
> a "udev without systemd" (although, as stated above, upstream supports |
57 |
> udev without systemd). I don't know the exact numbers, but it's my |
58 |
> impression (by reading -dev and -user), that eudev is used in Gentoo |
59 |
> (and only Gentoo) by a handful of people. The great majority is using |
60 |
> sys-fs/udev, and I'm willing to bet that more people are using systemd |
61 |
> directly than eudev. |
62 |
> |
63 |
>> Maybe now it's time for me to look |
64 |
>> into making a change of some type? I see eudev in portage, but not |
65 |
>> mdev. |
66 |
> |
67 |
> Using eudev will gain you nothing; the FHANDLE change will reach them |
68 |
> eventually. If you use mdev, you will have a noticeable loss of |
69 |
> functionality. I think even less people use mdev than eudev. |
70 |
> |
71 |
>> A (really, really, really) quick scan of the current install docs |
72 |
>> makes me think sysvinit/OpenRC/udev is still the default for new |
73 |
>> installs. Is this true? |
74 |
> |
75 |
> Yes, it's true, and no one will propose changing this, at least in the |
76 |
> near future. And even if systemd becomes the standard Gentoo init |
77 |
> system, OpenRC will be (almost surely) supported until the end of |
78 |
> times. |
79 |
> |
80 |
>> If so why is this kernel change being |
81 |
>> required? |
82 |
> |
83 |
> Because is new functionality provided by the kernel required by |
84 |
> *udev*, not (necessarily) systemd. Happens all the time; new |
85 |
> technology in the kernel is pretty useless if userspace doesn't start |
86 |
> taking advantage of it. |
87 |
> |
88 |
|
89 |
Understood. |
90 |
|
91 |
>> Also, I seem to have virtual/udev installed which says it's about |
92 |
>> enabling switching between udev & eudev. However there are no files |
93 |
>> associated with virtual/udev. (equery files virtual/udev returns |
94 |
>> nothing) |
95 |
> |
96 |
> That's why it's a virtual; a virtual pulls in different |
97 |
> implementations of the (in theory) same functionality. |
98 |
> |
99 |
>> It appears I cannot install eudev without removing udev so |
100 |
>> this seems a big step to take: |
101 |
> [ snip] |
102 |
> |
103 |
> It is a big step to take, and it will gain you nothing: eventually, |
104 |
> eudev *will* require FHANDLE, unless they diverge even more from |
105 |
> upstream, a thing I believe they cannot afford to do. |
106 |
> |
107 |
>> At this point I'm not even sure what my other questions might be as |
108 |
>> I'm just trying to get my head around what others are using these |
109 |
>> days. |
110 |
> |
111 |
> Well, it's undeniable that systemd usage is on the raising everywhere, |
112 |
> including Gentoo (specially since GNOME pulls it in). I myself use |
113 |
> systemd, and could not be happier. |
114 |
> |
115 |
> However, OpenRC is (and will be for the foreseeable future) the |
116 |
> default init system. |
117 |
|
118 |
Humm. OK, so I've updated my main spinning rust kernel for FHANDLE. No |
119 |
problems there. sysvinit/OpenRC/udev. All good. |
120 |
|
121 |
As I write this I'm in my SSD backup Gentoo install. I haven't used it |
122 |
in awhile so I'm emerging 668 packages. System setup as above but |
123 |
maybe I'll consider switching this one to systemd just as a trial. At |
124 |
this time it's not important on my personal machines. However my 86 |
125 |
year old father is the last Gnome holdout in the family. I've not |
126 |
updated his box in quite awhile (cognitive issues, fewer GUI changes |
127 |
are better for him) However if I do update then it will likely be |
128 |
Gnome so having at least a little experience with systemd might be |
129 |
good. |
130 |
|
131 |
|
132 |
>> I do have a second Gentoo install on this system on an SSD so |
133 |
>> (once updated) I could do a switch there as a test. |
134 |
> |
135 |
> My suggestion is for you to enable FHANDLE. From the kernel: |
136 |
> |
137 |
<SNIP> |
138 |
|
139 |
Done, no noticeable impact after 20 minutes. All good. |
140 |
|
141 |
> |
142 |
> So just enable the thing and go on with your life. |
143 |
> |
144 |
> My 0.02 ${CURRENCY}. |
145 |
> |
146 |
> Regards. |
147 |
> -- |
148 |
> Canek Peláez Valdés |
149 |
> Posgrado en Ciencia e Ingeniería de la Computación |
150 |
> Universidad Nacional Autónoma de México |
151 |
> |
152 |
|
153 |
Again, THANKS for a wonderful response with lots of good information. |
154 |
We're lucky to have you as one of the long-time Gentoo guys. I for one |
155 |
greatly appreciate what little I understand. :-) |
156 |
|
157 |
Cheers, |
158 |
Mark |