Re: Updating the kernel

2013-11-23 Thread Vasiliy Tolstov
2013/11/22  :
> The usual stock answer is "run two instances with some sort of 
> High-Availability
> package between the two of them". Fail over to one instance, reboot the 
> second,
> then fail over to the now-rebooted second instance and reboot the first.  I've
> done that on SGI boxes running CXFS and NFS - the NFS client machines see only
> a 2-3 second pause.


Usualy, but my use case different. What about my problem =) ? i think
in that case ksplice not very bad.

-- 
Vasiliy Tolstov,
e-mail: v.tols...@selfip.ru
jabber: v...@selfip.ru

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


Re: Updating the kernel

2013-11-22 Thread Valdis . Kletnieks
On Fri, 22 Nov 2013 12:21:59 +0400, Vasiliy Tolstov said:

> After some time i need to update kernel. How can i deal with it with
> minimal downtime not using ksplice?
> Kexec?

The usual stock answer is "run two instances with some sort of High-Availability
package between the two of them". Fail over to one instance, reboot the second,
then fail over to the now-rebooted second instance and reboot the first.  I've
done that on SGI boxes running CXFS and NFS - the NFS client machines see only
a 2-3 second pause.

(The bonus is that since the two boxes do heartbeat, it also means that if
one locks up or crashes, the other can seize control and continue processing
without users noticing.  So it's of benefit not just for updating the kernel.


pgpxo_n8P7Lc1.pgp
Description: PGP signature
___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


Re: Updating the kernel

2013-11-22 Thread Vasiliy Tolstov
2013/11/20 Soham Chakraborty :
> Sure, sure - I do. I actually adore it ;)


Sorry for up old thread about ksplice. But does linux have
alternatives? For example i have server with some vps (kvm) and not
have shared storage.
After some time i need to update kernel. How can i deal with it with
minimal downtime not using ksplice?
Kexec?

-- 
Vasiliy Tolstov,
e-mail: v.tols...@selfip.ru
jabber: v...@selfip.ru

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


Re: Updating the kernel

2013-11-20 Thread Soham Chakraborty
Sure, sure - I do. I actually adore it ;)


On Wed, Nov 20, 2013 at 12:58 PM,  wrote:

> On Tue, 19 Nov 2013 15:39:06 -0500, Soham Chakraborty said:
> > Vladis, I hear ya and agree to that. Problem is I have seen big and by
> big,
> > I mean big infrastructures asking for ksplice since certain sales
> > people of certain company introduced them to the utopia that is called
> > downtime-less-patching-and-upgrading. And obviously, if you have worked
> > with the CLI a bit less than most of us have already had, you get the
> sweet
> > inclination to go with sales and you know, voila.
>
> Don't you just love when management makes decisions based on 8.5x11 color
> glossies? ;)
>
___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


Re: Updating the kernel

2013-11-20 Thread Valdis . Kletnieks
On Tue, 19 Nov 2013 15:39:06 -0500, Soham Chakraborty said:
> Vladis, I hear ya and agree to that. Problem is I have seen big and by big,
> I mean big infrastructures asking for ksplice since certain sales
> people of certain company introduced them to the utopia that is called
> downtime-less-patching-and-upgrading. And obviously, if you have worked
> with the CLI a bit less than most of us have already had, you get the sweet
> inclination to go with sales and you know, voila.

Don't you just love when management makes decisions based on 8.5x11 color 
glossies? ;)


pgpKr1b4DJsOE.pgp
Description: PGP signature
___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


Re: Updating the kernel

2013-11-19 Thread Soham Chakraborty
Vladis, I hear ya and agree to that. Problem is I have seen big and by big,
I mean big infrastructures asking for ksplice since certain sales
people of certain company introduced them to the utopia that is called
downtime-less-patching-and-upgrading. And obviously, if you have worked
with the CLI a bit less than most of us have already had, you get the sweet
inclination to go with sales and you know, voila.


On Tue, Nov 19, 2013 at 2:16 PM,  wrote:

> On Tue, 19 Nov 2013 09:48:27 -0500, Soham Chakraborty said:
> > I don't really think ksplice has garnered much love from upstream.
>
> The most common word used upstream to describe ksplice is "bletcherous".
>
> The reason it's disliked is because it's a poor solution for the problem.
> Although ksplice-like technology was used for years to upgrade telco
> switches on the fly, that was motivated by two major factors:
>
> 1) Nobody at a telco wants to drop dial tone while a switch reboots.
> 2) Telco switches are building-sized and expensive, so HA failover wasn't a
> realistic option.
>
> Although the first is still an issue for many sites, there's little or no
> justification in 2013 for the second.
>
> If you're in the sort of environment where you really need the sort of
> uptime
> that drive you to consider ksplice, you *really* should be doing load
> balancing and HA failover with heartbeats - that will not only allow you
> to actually reboot each server cleanly, but *also* protect you against
> blown
> DIMMs, crashed system disks, and all the *other* whoopsies that can cost
> you one or two nine's of reliability.
>
> Seriously - if you can't afford the downtime to reboot, youy can't afford
> *NOT* to be doing a full HA configuration - and possibly looking at
> geographic separation of the hot failover site.
>
___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


Re: Updating the kernel

2013-11-19 Thread Valdis . Kletnieks
On Tue, 19 Nov 2013 09:48:27 -0500, Soham Chakraborty said:
> I don't really think ksplice has garnered much love from upstream.

The most common word used upstream to describe ksplice is "bletcherous".

The reason it's disliked is because it's a poor solution for the problem.
Although ksplice-like technology was used for years to upgrade telco
switches on the fly, that was motivated by two major factors:

1) Nobody at a telco wants to drop dial tone while a switch reboots.
2) Telco switches are building-sized and expensive, so HA failover wasn't a
realistic option.

Although the first is still an issue for many sites, there's little or no
justification in 2013 for the second.

If you're in the sort of environment where you really need the sort of uptime
that drive you to consider ksplice, you *really* should be doing load
balancing and HA failover with heartbeats - that will not only allow you
to actually reboot each server cleanly, but *also* protect you against blown
DIMMs, crashed system disks, and all the *other* whoopsies that can cost
you one or two nine's of reliability.

Seriously - if you can't afford the downtime to reboot, youy can't afford
*NOT* to be doing a full HA configuration - and possibly looking at
geographic separation of the hot failover site.


pgpF_PdAn4IEv.pgp
Description: PGP signature
___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


Re: Updating the kernel

2013-11-19 Thread Soham Chakraborty
I don't really think ksplice has garnered much love from upstream. I for
one, know that rpm based distros don't support it.

Soham


On Tue, Nov 19, 2013 at 12:52 AM, Mandeep Sandhu <
mandeepsandhu@gmail.com> wrote:

> Yes, Ksplice offers this feature. Though check with them if your
> specific distro is supported. Or if you're compiling your own kernel
> then I guess you'll have to send them the new image which they convert
> to a reboot-less image which can be applied to a running system.
>
> -mandeep
>
> On Tue, Nov 19, 2013 at 10:55 AM, Shraddha Kamat 
> wrote:
> > Is it possible to keep the kernel updated to upstream without ever
> > rebooting the system ? Ksplice ??
> >
> > Regards,
> > Shraddha
> >
> >
> > ___
> > Kernelnewbies mailing list
> > Kernelnewbies@kernelnewbies.org
> > http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies


Re: Updating the kernel

2013-11-18 Thread Mandeep Sandhu
Yes, Ksplice offers this feature. Though check with them if your
specific distro is supported. Or if you're compiling your own kernel
then I guess you'll have to send them the new image which they convert
to a reboot-less image which can be applied to a running system.

-mandeep

On Tue, Nov 19, 2013 at 10:55 AM, Shraddha Kamat  wrote:
> Is it possible to keep the kernel updated to upstream without ever
> rebooting the system ? Ksplice ??
>
> Regards,
> Shraddha
>
>
> ___
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

___
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.org
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies