Re: Ubuntu Server seeded package review
On Mon, 09 Dec 2013 12:13:22 -0600 Chris J Arges wrote: > On 12/09/2013 11:50 AM, Serge Hallyn wrote: > > Chris Arges (cc:d) has looked into this before in-depth. But I > > don't seem to have the email with his conclusions. Chris, could > > you summarize here what you had found when you looked into our > > previous suggestion to not enable ntp in guests? > > > > Hi, > > Here is the original thread about this topic: > https://lists.ubuntu.com/archives/ubuntu-server/2013-April/006556.html > > Originally we had recommended _not_ to use NTP on VMs, but after > researching this a bit further it seemed clear that NTP should work > perfectly fine. The modification I made is updated here: > https://help.ubuntu.com/community/KVM/FAQ#Should_ntp_be_used_for_time_synchronisation.3F > > My statement was pretty vague on purpose. > If you are doing lightweight stuff when you boot the VM the kvmclock > will setup the clocksource just fine and we expect the system time to > not drift too much while the VM is up. > For heavy duty stuff where you have many VMs, they run for a long > time , or never shutdown/reboot the machine, it makes sense to setup > NTP client on the VM using the host machine as the ntp server. I would like to point out that my original email -- and the start of this thread -- was not fixed on having NTP running on VMs in particular, but *servers* generically. So, I guess, we *should*: * be running NTP on bare-metal servers; * be running NTP on VMs, set to sync with the host. Of course, this is a simplification: on a complex environment, a single source for time sync should be selected for *all* bare-metals. Which one, if a stratum 1 or 2 (or even lower) is not a problem -- as long as all the machines are syncing to the same time provider. But, on a default install, using the *.ntp.ubuntu.com providers, we would have this, even if all the bare-metals directly sync to *.ntp.ubuntu.com (but this is would not be ideal). ..C.. -- ab alio expectes alteri quod feceris signature.asc Description: PGP signature -- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
Re: is memtest86+ useful in ubuntu-standard ?
On 10 December 2013 14:47, Scott Moser wrote: > Hey all, > Looking at the contents of the cloud images, memtest86+ is one of the > packages that I questioned the necessity of in a cloud image. > That is in the cloud images as cloud images are ubuntu-server and > ubuntu-standard tasks plus a small amount of other packages. > > memtest86+ was added to standard on 2006-06-20. > > Do we still feel that it is necessary as part of the default install ? > > If people do still feel it is useful as part of the default install, is > there a reasonable way we can explicitly exlude it from cloud images > without removing 'ubuntu-standard' ? I don't see any reason to have it installed. I would like to still have it on the bootable server CD-roms, it's handy when something is suspected wrong. -Rob -- Robert Collins Distinguished Technologist HP Converged Cloud -- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
is memtest86+ useful in ubuntu-standard ?
Hey all, Looking at the contents of the cloud images, memtest86+ is one of the packages that I questioned the necessity of in a cloud image. That is in the cloud images as cloud images are ubuntu-server and ubuntu-standard tasks plus a small amount of other packages. memtest86+ was added to standard on 2006-06-20. Do we still feel that it is necessary as part of the default install ? If people do still feel it is useful as part of the default install, is there a reasonable way we can explicitly exlude it from cloud images without removing 'ubuntu-standard' ? Thanks, Scott -- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
Cloud-images: Announcing UEFI and BIOS/GPT images for Trusty
Starting with Ubuntu 14.04 LTS, the Cloud Images for AMD64 will include
a new UEFI disk image. This new image has been designed to be as
flexiable as possible, supporting not only UEFI, but BIOS/GPT (current
images are BIOS/MBR) and support for P{V,Y}GRUB's w/ GPT support. As a
result, these new images should work on a variety of hypervisor
platforms. The daily image will be available at [1] once they exit the
build system within the next several hours.
The following output show the layout of the disk:
ubuntu@gpt-test:~$ sudo parted /dev/vda -- print
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Number Start End SizeFile system Name Flags
127 1049kB 2097kB 1049kB BIOS boot partition bios_grub
128 2097kB 89.1MB 87.0MB fat32EFI System boot
1 89.1MB 10.7GB 10.6GB ext4 Linux filesystem
The layout is explained as followed:
* Partition 127 is for BIOS/GPT booting
* This partition is not mounted.
* Partition 128 is used for the UEFI installation. It is mounted to
/boot/efi
* GRUB UEFI is configured to look at partition 1's /boot/grub/grub.cfg
* UEFI is configured as a removal disk
* In order to register the disk in the hypervisor's NVRAM, you'll
need to run
grub-install again.
* Partition 1 is maintained as the traditional 'cloudimg-rootfs'
* /boot/grub/menu.lst will be maintained for P{V,Y}GRUB.
Note: due to a kernel bug [2], when these images are booted with the
root disk using a virtio device, /dev/vda{127,128} device nodes are not
created. Therefore, for the time being, you will need to use a
non-virtio device in order for these images to boot properly.
Thanks,
Ben
[1]
http://cloud-images.ubuntu.com/trusty/current/trusty-server-cloudimg-amd64-uefi1.img
[2] https://bugs.launchpad.net/bugs/1258631
--
Ben Howard
ben.how...@canonical.com
Canonical
GPG ID 0x5406A866
signature.asc
Description: OpenPGP digital signature
--
ubuntu-devel mailing list
ubuntu-devel@lists.ubuntu.com
Modify settings or unsubscribe at:
https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
Re: Ubuntu Server seeded package review
On 12/09/2013 11:50 AM, Serge Hallyn wrote: > Chris Arges (cc:d) has looked into this before in-depth. But I don't > seem to have the email with his conclusions. Chris, could you summarize > here what you had found when you looked into our previous suggestion to > not enable ntp in guests? > Hi, Here is the original thread about this topic: https://lists.ubuntu.com/archives/ubuntu-server/2013-April/006556.html Originally we had recommended _not_ to use NTP on VMs, but after researching this a bit further it seemed clear that NTP should work perfectly fine. The modification I made is updated here: https://help.ubuntu.com/community/KVM/FAQ#Should_ntp_be_used_for_time_synchronisation.3F My statement was pretty vague on purpose. If you are doing lightweight stuff when you boot the VM the kvmclock will setup the clocksource just fine and we expect the system time to not drift too much while the VM is up. For heavy duty stuff where you have many VMs, they run for a long time , or never shutdown/reboot the machine, it makes sense to setup NTP client on the VM using the host machine as the ntp server. > Quoting Seth Arnold (seth.arn...@canonical.com): >> On Thu, Dec 05, 2013 at 05:15:41PM -0600, C de-Avillez wrote: >>> Although I am probably hammering a rather cold iron, I still fail to >>> understand why ntp is not installed by default. I would expect precise >>> timekeeping to be something important on a server (instead of allowing >>> the time to drift slowly). >> >> I would like to hear from An Expert if ntpd, ntpdate, ptpd, etc., are >> reasonable things to install in virtual machine guest environments. >> >> My personal suspicion is that when a virtual machine host runs ntpd, >> guests should not run ntpd, since two daemons attempting to skew the >> clock sounds like a recipe for highly chaotic behavior. ntpdate would >> be alright since it does not attempt to manage clock skew. ptpd no idea. >> This is why the guest should use the host as the ntp server. Instead of both reaching out to ntp.ubuntu.com for example. >> When the virtual machine host does not run ntpd, I suspect ntpd, ntpdate, >> ptpd, are all fine things to run in the guests. >> >> I'd love to know for certain what the best practices are. It might >> influence the default package installs. >> I posted this earlier on ubuntu-server ML because I wasn't an expert. So I'm open to other suggestions on how to accomplish this. --chris j arges >> Thanks > > > >> -- >> ubuntu-devel mailing list >> ubuntu-devel@lists.ubuntu.com >> Modify settings or unsubscribe at: >> https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel > -- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
Re: Ubuntu Server seeded package review
Chris Arges (cc:d) has looked into this before in-depth. But I don't seem to have the email with his conclusions. Chris, could you summarize here what you had found when you looked into our previous suggestion to not enable ntp in guests? Quoting Seth Arnold (seth.arn...@canonical.com): > On Thu, Dec 05, 2013 at 05:15:41PM -0600, C de-Avillez wrote: > > Although I am probably hammering a rather cold iron, I still fail to > > understand why ntp is not installed by default. I would expect precise > > timekeeping to be something important on a server (instead of allowing > > the time to drift slowly). > > I would like to hear from An Expert if ntpd, ntpdate, ptpd, etc., are > reasonable things to install in virtual machine guest environments. > > My personal suspicion is that when a virtual machine host runs ntpd, > guests should not run ntpd, since two daemons attempting to skew the > clock sounds like a recipe for highly chaotic behavior. ntpdate would > be alright since it does not attempt to manage clock skew. ptpd no idea. > > When the virtual machine host does not run ntpd, I suspect ntpd, ntpdate, > ptpd, are all fine things to run in the guests. > > I'd love to know for certain what the best practices are. It might > influence the default package installs. > > Thanks > -- > ubuntu-devel mailing list > ubuntu-devel@lists.ubuntu.com > Modify settings or unsubscribe at: > https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel -- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
Re: Ubuntu Server seeded package review
On Fri, 2013-12-06 at 11:43 -0800, Seth Arnold wrote: > On Thu, Dec 05, 2013 at 05:15:41PM -0600, C de-Avillez wrote: > > Although I am probably hammering a rather cold iron, I still fail to > > understand why ntp is not installed by default. I would expect precise > > timekeeping to be something important on a server (instead of allowing > > the time to drift slowly). > > I would like to hear from An Expert if ntpd, ntpdate, ptpd, etc., are > reasonable things to install in virtual machine guest environments. > > My personal suspicion is that when a virtual machine host runs ntpd, > guests should not run ntpd, since two daemons attempting to skew the > clock sounds like a recipe for highly chaotic behavior. ntpdate would > be alright since it does not attempt to manage clock skew. ptpd no idea. > > When the virtual machine host does not run ntpd, I suspect ntpd, ntpdate, > ptpd, are all fine things to run in the guests. > > I'd love to know for certain what the best practices are. It might > influence the default package installs. > > Thanks My personal experience with a VM server running 12.04 and multiple VMs with various Linux and Windows distros is that while the server is running ntpd, the guests don't appear to get updated correctly from the host. Some of the systems that I have taken the time to point ntpd to an internal server (we're behind a corporate firewall) are ok, the others tend to get skewed after a bit. No idea why. -- -- Tobin Davis Yes, we will be going to OSI, Mars, and Pluto, but not necessarily in that order. -- George Michaelson -- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
Re: Ubuntu Server seeded package review
Hi On 8 Dec 2013 17:03, "Seth Arnold" wrote: > > On Thu, Dec 05, 2013 at 05:15:41PM -0600, C de-Avillez wrote: > > Although I am probably hammering a rather cold iron, I still fail to > > understand why ntp is not installed by default. I would expect precise > > timekeeping to be something important on a server (instead of allowing > > the time to drift slowly). > > I would like to hear from An Expert if ntpd, ntpdate, ptpd, etc., are > reasonable things to install in virtual machine guest environments. > > My personal suspicion is that when a virtual machine host runs ntpd, > guests should not run ntpd, since two daemons attempting to skew the > clock sounds like a recipe for highly chaotic behavior. ntpdate would > be alright since it does not attempt to manage clock skew. ptpd no idea. > > When the virtual machine host does not run ntpd, I suspect ntpd, ntpdate, > ptpd, are all fine things to run in the guests. > > I'd love to know for certain what the best practices are. It might > influence the default package installs. > > Thanks > > -- > ubuntu-devel mailing list > ubuntu-devel@lists.ubuntu.com > Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel > I have seen a few cases where VMs had clock skew due drift. Imho, It is advisable to leave this in based off the support requests I have seen in past few years. -- ritz -- ubuntu-devel mailing list ubuntu-devel@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
