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Bug#335230: More stub code



Alle 09:49, mercoledì 26 ottobre 2005, hai scritto:

> Yes, that was my first implementation actually. But the Device Number in
> evms_query info doesn't match the real device maj/min and I really don't
> know which one might be useful when filtering with findByDevNo eg:
>
> # evms_query info /dev/evms/e3
> Name: /dev/evms/e3
> Type: Volume
> Device Number: 0:0
> Size (sectors): 19531006
> Filesystem: Unknown
>
> # evms_query disks /dev/evms/e3
> hda
>
> # ls -l /dev/hda
> brw-rw----  1 root disk 3, 0 2005-10-25 14:39 /dev/hda
> My current evms setup is really stupid so I'm probably missing a lot of
> more complex or even corner cases. :)

Try to boot it from a evms volume rootfs, or check it with a custom cd, the 
right way to migrate to me it seems:
- live cd and evms_activate, generate emvs enabled initrd
- reboot from evms root and evms_activate.
- go test setup

> And in my case 'Device Number' is always 0:0 ...hmmm...

Not in my case, 0,0 seems to me for unactive objects... Maybe it is just not 
an ACTIVE disk.

# evms_query info /dev/evms/lvm2/sicuro/usr64
Name: /dev/evms/lvm2/sicuro/usr64
Type: Volume
Device Number: 253:41
Size (sectors): 11534336
Filesystem: XFS
# evms_query disks /dev/evms/lvm2/sicuro/usr64
sda
sdb
sdc
# ls -l /dev/sda
brw-rw----  1 root disk 8, 0 2005-10-26 17:15 /dev/sda

> And more: in case an evms volume spans multiple devices shall we provide
> an array of devno? Isn't ok to have an array of disk names (currently
> EvmsTab->devices) and loop on them in tryEvms (as in the tryRaid case)?

For enabling evms in yaird, now it seems to me that we have only to provide 
the right set (or all as we discussed) of plugins and add filesystem kernel 
module (e.g. xfs.ko) for the root device evms volume, for evms needed regions 
(md-mod.ko,raid5.ko,dm-mod.ko) and for disk (sata-nv), so some of the 
informations can be retrieved by volume, region and segment plugins. (in this 
example, in order the plugin strings : XFS, MDRaid5RegMgr, 

So full series of commands, outputs and actions (->) for 
booting  /dev/evms/lvm2/sicuro/usr64 on my system:

#  evms_query info | grep Version | head -1 | cut -d ' ' -f 3
2.5.3
-> $version=2.5.3
# evms_query plugins /dev/evms/lvm2/sicuro/usr64
XFS 
-> add xfs.ko, /lib/evms/$version/xfs-1.0.11.so

# evms_query regions /dev/evms/lvm2/sicuro/usr64
lvm2/sicuro/usr64
md/md1
md/md2
# evms_query regions /dev/evms/lvm2/sicuro/usr64 | xargs -i evms_query plugins  
\{\} | uniq
LVM2
MDRaid5RegMgr
-> add md,dm,raid5 .ko ; md-1.1.18.so, lvm2-1.0.3.so

# evms_query segments /dev/evms/lvm2/sicuro/usr64 | xargs -i evms_query 
plugins  \{\} | uniq
DosSegMgr
-> partition type dos .ko ; dos-1.1.14.so

# evms_query disks /dev/evms/lvm2/sicuro/usr64
sda
sdb
sdc
# evms_query disks /dev/evms/lvm2/sicuro/usr64 | xargs -i evms_query plugins  
\{\} | uniq
LocalDskMgr
-> no info on needed sata-nv ;  disk-1.2.11.so

I think that also in the supporting-plugin version should be left an option to 
include all evms plugins right now and enabled by default.

> Marco, could you also provide full output in your case?

Attached output of evms_gather_info.

> > The properties look OK to find devices, but don't yet provide enough
> > information to decide whether to load raid0/raid5.  The crude fix is
> > to just load them always ...   Marco, opinions?

As above, raid? and md information are given by "evms_query regions <devname> 
| xargs -i evms_query plugins

so we maybe need also region information on evmstab.

> > Here's a twist: what if there are two devices on evms that yaird
> > accesses? So far we've been able to do a depth-first walk over devices
> > needed, but if evms_activate does not take an argument indicating which
> > device we're trying to activate, we'll need to find an alternative
> > approach.
>
> evms_activate will try to discover them all. I still don't get why this is
> an issue but this is due to limited computing power in my brain :)

Me too right now. :-)

So Erik, do you have enough code to produce an experimental release of yaird? 

is 0.12 coming soon? :-)


-- 
ESC:wq

Attachment: evms_gather_info-output.bz2
Description: BZip2 compressed data


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