1 |
On Feb 26, 2012 2:05 AM, "Robert David" <robert.david.public@×××××.com> |
2 |
wrote: |
3 |
> |
4 |
> V Sat, 25 Feb 2012 10:32:20 -0800 |
5 |
> Grant <emailgrant@×××××.com> napsáno: |
6 |
> |
7 |
> > >> >> I need to test a kernel config change on a remote system. Is |
8 |
> > >> >> there a safe way to do this? The fallback thing in grub has |
9 |
> > >> >> never worked for me. When does that ever work? |
10 |
> > >> > |
11 |
> > >> > |
12 |
> > >> > You can press ESC in the Grub screen and it will take you to |
13 |
> > >> > text-only mode. There, you select an entry, press "e" and edit |
14 |
> > >> > it. Press ENTER when you're finished, and then press "b" to boot |
15 |
> > >> > your modified entry. |
16 |
> > >> > |
17 |
> > >> > That way, you can boot whatever kernel you want if the current |
18 |
> > >> > one doesn't work. |
19 |
> > >> |
20 |
> > >> I can't do that remotely though. I'm probably asking for something |
21 |
> > >> that doesn't exist. |
22 |
> > >> |
23 |
> > >> - Grant |
24 |
> > >> |
25 |
> > > |
26 |
> > > Don't do that if you don't have some tool like KVM, or other remote |
27 |
> > > management of the server. Or if it is available in the data center, |
28 |
> > > just call them and order this service for the time you need to do |
29 |
> > > updates. |
30 |
> > > |
31 |
> > > This is why I don't use gentoo on servers any more, just because |
32 |
> > > I rather stay safe than sorry. |
33 |
> > |
34 |
> > How is another distro different in this situation? |
35 |
> > |
36 |
> > - Grant |
37 |
> |
38 |
> Just because when using distros like Centos/RHEL or Debian stable, you |
39 |
> have very little chance that the kernel released will fail. Due to |
40 |
> extensive testing, user base and update policy. And major kernel update |
41 |
> you done only once in few years and the transition is tested before |
42 |
> release done (though you are supposed to test yourself to be safe). |
43 |
> |
44 |
> This is not saying that gentoo is bad, I'm very big fan of gentoo. |
45 |
> But you have to concern where it use and where not. |
46 |
> |
47 |
> Robert. |
48 |
> |
49 |
|
50 |
Anecdotal, but... |
51 |
|
52 |
I once had an Ubuntu VM that can't shutdown after a kernel update. First |
53 |
boot after update went well, but when I rebooted it again, it pegged its |
54 |
vCPUs at 100% before I ordered the Xen hypervisor to put it out of its |
55 |
misery. |
56 |
|
57 |
The bug was apparently in the portion of the kernel running in the primary |
58 |
CPU that's responsible for shutting down the other CPUs before cutting the |
59 |
power. And IIRC, this bug affects all multi-processor configuration. |
60 |
|
61 |
So, as you can see, binary distros can still fuck up royal time. Not to |
62 |
mention that if you have an exotic configuration, support for your |
63 |
configuration might not be built into the kernel by the distro. |
64 |
|
65 |
Somehow I believe people deploying Gentoo servers will be much more |
66 |
careful... |
67 |
|
68 |
Rgds, |