[Ovirt-devel] a couple of questions

[Mike Burns]

On Tue, 2010-05-18 at 19:39 +1000, Geoff O'Callaghan wrote:
> On 15/05/10 11:47, Mike Burns wrote:
> > On Sat, 2010-05-15 at 10:21 +1000, Geoff O'Callaghan wrote:
> >> Hi There,
> >>
> 
> [snip]
> 
> >> Q2.
> >>
> >> I did a build of the ovirt git next branch and created the
> >> ovirt-node-iso to test and I noticed that it had an unexpected result
> >> related to thinking that my single  standard local sata drive was part
> >> of a multipath configuration.  This was due to a null
> >> /etc/multipath.conf file which is created specifically as part of the
> >> node/recipe/common-post.ks
> >>
> >> What is the plan in this area?   Will multipath enablement be forced or
> >> as an option to enable it on the ovirt-config-storage menu?
> >
> > Multipath is the default for all devices that have wwids.  As of now,
> > there is no plan to change this.  The decision to use multipath for all
> > devices if possible makes the setup much cleaner and doesn't introduce
> > any negatives that I see.  It might be possible to make it configurable,
> > but I don't think that it's trivial to do so.
> 
> ok, that's fine and is probably a wise choice given the environment 
> ovirt is likely to find itself :)
> 
> Anyway, the problem with my system is definitely related to how the 
> multipath device gets set up as you can see in the attached log.

Yes, we have a bug in the code that figures out multipath devices.  It
seems that some devices end up providing a wwid that contains spaces
which breaks the code.  I hope to have a fix posted today.  

Instead of picking up 
"/dev/mapper/1ATA WDC WD1200JB-00FUA0 WD-WCAES102461"
we instead got:
"/dev/mapper/1ATA"
> 
> >>
> >>
> >> Q3.
> >>
> >> If I change common-post.ks to add a /etc/multipath.conf with a blacklist
> >> of '*' it then correctly identifies my local drive for the install -
> >> however, when doing the storage allocation it gets the sizes wrong so
> >> there is a calculation bug somewhere.  I didn't see it in bugzilla so
> >> it's either a new  bug or something wrong with my specific setup or both
> >> :)   Is it something someone has noticed?
> >
> > I haven't noticed any calculation errors recently, though I admit that I
> > haven't looked that closely recently.  When using multipath, do you see
> > the same issue?
> >
> > Can you provide the ovirt.log file from the install that shows the
> > incorrect size?
> 
> The incorrect size came when I had a multipath.conf file that 
> blacklisted '*'.
> 
> In the case of the ovirt.log file attached I am running a vanilla build 
> from the git next branch.
> 
> As you can see from the log it makes a bit of a mess of it.  To 
> supplement the log I have:
> 
> [root at localhost ~]# multipath -ll
> 1ATA     WDC WD1200JB-00FUA0                     WD-WCAES102461 dm-1 
> ATA,WDC WD1200JB-00F
> size=112G features='0' hwhandler='0' wp=rw
> `-+- policy='round-robin 0' prio=1 status=active
>    `- 6:0:0:0 sda 8:0 active ready running
> 
> [root at localhost ~]# dmsetup ls --target=multipath
> 1ATA     WDC WD1200JB-00FUA0                     WD-WCAES1024619	(253, 1)
> 
> and attached as log.txt I have the output of a bash -x ovirt-config-storage
> 
> ps.  sorry about the delay getting back to you - hopefully you can spot 
> the problem.

It looks like neither log was for incorrect space issue.  Both of them
show a multipath device being detected.  It also looks like it
determined that /dev/sda was 114473 MB which is approx 112 GB.  This is
the same value that mutlipath output above shows.

I did notice a few of these messages:

WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util
sfdisk doesn't support GPT. Use GNU Parted.

I'll look into those as well.

Mike
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