Cluster Storage Sync Migrate Shared!?

plewka

Member
Sep 28, 2009
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This is a general question regarding storage model.
Probably answered many times before...but I wasn't able to extract the info.

We're using local storage only. In past we used symlinks to
"simulate" the same directory structure on all nodes. This basicly worked
but had some issues and finally we decided to do a clean installation
on two new nodes.

We use RAID1with2 for System and RAID10with4 for
VM/ISO/Backup-Storage on both Nodes.
We think it's a good idea to seperate the system because of
IO-Decoupling and easy (and riskless) upgrading of PVE.
We mapped the Storage to /vz and entered two Directory Storages
(shared _not_ checked). One for template/iso and one for images.
What's the exact meaning of shared here? If shared is checked,
PVE things its physically the same, mounted two times?!
What happens if shared is not checked? Rsync?

One thing which is a little inconsistent here is: for images you have to
enter /vz/images, for iso you only habe to enter /vz/templates while
iso is created automaticly. At least its's strange if you don't know
PVEs history.

Finally I do no longer understand the idea of the sync policy.
Which directorys are synced ofer the nodes, which are not?!
There is a difference of taking these new storage volumes compared
to using the default directories in /var/lib/vz, isn't there?

The idea of using the PVE1.5 storages is having an external storage,
not a local storage on the node, right?

Currently my cluster is no more a cluster;-)
Is there a possibility to get back the basic (offline) migration and iso
sharing without doing symlinks to /var/lib/vz or so?!
I would like to use storage on seperate partition and get it synced
to the other nodes.

For sure we intend to use DRBD again, but only for critical machines
because of IO-Performance an limitation of DRBDviaGigabit.

Many thanks in advance

Joern Plewka
 
One thing which is a little inconsistent here is: for images you have to
enter /vz/images, for iso you only habe to enter /vz/templates while
iso is created automaticly. At least its's strange if you don't know
PVEs history.

Sorry, but template storage is a special case, and AFAIK it only works
when mounted under /var/lib/vz/...

Finally I do no longer understand the idea of the sync policy.
Which directorys are synced ofer the nodes, which are not?!
There is a difference of taking these new storage volumes compared
to using the default directories in /var/lib/vz, isn't there?

only iso an template storage under /var/lib/vz/ are synced - nothing else.

The idea of using the PVE1.5 storages is having an external storage,
not a local storage on the node, right?

Currently my cluster is no more a cluster;-)
Is there a possibility to get back the basic (offline) migration and iso
sharing without doing symlinks to /var/lib/vz or so?!

no

I would like to use storage on seperate partition and get it synced
to the other nodes.

just use cron and rsync - or better, a shared storage (nfs).