Earth Computing

[Alvin]

On Thursday 28 January 2010 09:31:00 Etienne Goyer wrote:
> > Alvin wrote:
> >>   Why not Ubuntu?
> >>   - ZFS (does not need much explanation)
> 
> Not looking to make excuse, but just so you know, ZFS on Linux is
> unlikely to happen due to licensing issue:
> 
>     http://en.wikipedia.org/wiki/ZFS#Linux

I know. It's still the most useful filesystem around, and we want to use the 
best tools for the job. LVM is not as flexible as ZFS. Maybe things will 
brighten for Linux when BTRFS comes around.

> >>   These run Jaunty because of the above bugs and because of a regression
> >>   [bug
> >> 
> >> 224138] "No NFS modules in karmic 32-bit"
> 
> Again, not trying to make excuse, and not sure I understand the problem
> correctly, but that sounds like an overstatement.  It seems like the
> -virtual kernel flavor is missing some modules (including those for
> NFS*v4*), but you could just as well use the -generic or -server flavor.
>  Or am I misunderstanding something?

Yes, virtio. The virtual kernels perform faster. In extreme cases, a 
calculation could take as much as 6 hours. You will run in stability issues 
when using the normal kernel. (Our old Solaris8 machines do the same in 6 
days.)
Besides, when the virtual machines were build, we had no choice due to this 
bug: [kvm guests not using virtio for networking lose network connectivity]
https://bugs.launchpad.net/bugs/286101

> >>   - [bug 374907] "libmotif3 crashes"
> 
> <...snip...>
> 
> >> Sometimes you hear: "it's open source. Don't complain and fix it
> >> yourself." That's partly true. I'm not a programmer, but I was able to
> >> patch libmotif3 to solve the crashes.
> >> The kind people in ubuntu-bugs also managed to convince me that I could
> >> package the new version of openmotif myself and put it in Debian. Maybe
> >> I'll learn how to do that, so that bug can at least be closed. I can
> >> understand that there is not a lot of interest in this package, but we
> >> need it and will probably need it for some time to come.
> 
> IIRC, the Citrix ICA client depends on OpenMotif (not sure which
> version), so that bug would be a biggie indeed if it breaks the ICA
> Client.  We have been using the ICA Client on hardy without any problem
> so far, but I am putting that on my radar.  Thanks for the heads up, I
> will be looking into it.

Thanks! There is also a [needs-packaging] bug report:
https://bugs.launchpad.net/bugs/462182

> >> What I can't understand is that there would be no interest in NFS. Is
> >> everyone using samba between unix machines these days?
> 
> To be honest, yes.  NFS is only really useful for read-only share, as
> NFS  < v4 does not have any form of authentication, where CIFS mount can
> be authenticated.  It is still not good enough, as the file operation
> themselves are not encrypted (supposed to come in Samba any time now),
> but it is a step in the right direction.  NFSv4, because of its reliance
> on Kerberos, is too hairy to set up in most case.
> 
> In general, I try to avoid NFS whenever possible, except for trivial
> things.  CIFS with Unix Extensions has been serving me well so far.

Is LTSP not heavily dependant on NFS? I think it's a mistake to throw the Unix 
way overboard in favour of MS Windows solutions. NFS and CIFS have different 
usage scenarios. There is certainly room for improvement, but that's why NFSv4 
exists. I can't remember if there were questions about file sharing technology 
in the Ubuntu Server Survey, but you should try to put it in a survey. I'm 
curious about the result.

Also, keep in mind that in some situations, security is not important. 
Security often comes at a price (complexity and speed). I admit, central user 
management is only partly functional in this company. Our current security 
system is based on the concept of 'User Private Groups'. That works fine over 
NFS (not v4). In order to use Akonadi on shared /home you do need NFSv4 due to 
locking issues. Implementation is tricky though.
Users need access to the same filesystems anyway. Of course they do make 
mistakes and erase files, or move them to the wrong place. That's why the 
regular ZFS snapshots can be so handy. Our network has been based around NFS 
for at least over 12 years, and it was quite a shock to see that computers did 
no longer boot after the update to Karmic.

> But thanks for your feedbacks, you are doing the right thing.  I am not
> working in the distro team (I am in Corporate Services), so I cannot do
> anything to help with your bugs directly, but I think it is a very good
> thing that we get this kind of feedback.

I must say I'm quite happy with this attention. Your offer for commercial 
support will certainly be accepted in light of the fact that there is interest 
to know what people are actually doing (or trying to do) with Ubuntu.