XOSTOR hyperconvergence preview

fred974

@ronan-a I just had a problem where I cannot deploy the XO Kubernetes recipe on our XOSTOR SR. It work with no problem on local storage. Could you please test if you are facing the same issue as us or if the issue is isolated to me?
Here is the post that make me realised the issue is with XOSTOR

andersonalipio

Hello all,

I got it working just fine so far on all lab tests, but one thing a couldn't find in here or other post related to using a dedicated storage network other then managemente network. Can it be modified? In this lab, we have 2 hosts with 2 network cards each, one for mgmt and vm external traffic, and the second should be exclusive for storage, since is way faster.

Swen

@andersonalipio said in XOSTOR hyperconvergence preview:

Hello all,

I got it working just fine so far on all lab tests, but one thing a couldn't find in here or other post related to using a dedicated storage network other then managemente network. Can it be modified? In this lab, we have 2 hosts with 2 network cards each, one for mgmt and vm external traffic, and the second should be exclusive for storage, since is way faster.

We are using a separate network in our lab. What we do is this:

get the node list from the running controller via

linstor node list

take a look at the node interface list via

linstor node interface list <node name>

modify each nodes interface via

linstor node interface modify <node name> default --ip <ip>

check addresses via this

linstor node list

Hope that helps!

andersonalipio

@Swen Thanks bud! It did the trick!

I did the interface modify commands on master only, it changed all hosts online with running guest vms and no downtime at all!

TheiLLeniumStudios

Is it possible to only use 2 hosts for XOSTOR?

Swen

@TheiLLeniumStudios It should be possible, but not recommended. You can end up in a split-brain-scenario.

olivierlambert

We do not want to support 2 hosts for now. In theory, you can work if you add a 3rd machine acting as a "Tie Breaker", but it's more complex to setup. However, for a home lab, that should be doable

Swen

@olivierlambert can you please provide an update or better a roadmap regarding the implementation of linstor in xcp-ng? I find it hard to understand in which status this project is at the moment. As you know we are really looking forward to use it in production with our Cloudstack installation. Thx for any news.

olivierlambert

We are close to a first release (at least a RC). That will be CLI-only, but we already have plans to replace the XOSAN UI in Xen Orchestra by XOSTOR

Swen

@olivierlambert thx for the quick reply! Does close mean days, weeks or month?

olivierlambert

RC weeks I think

niko7

@olivierlambert will XOSTOR support deduplication?

olivierlambert

Not yet, but I think I've read LINSTOR supports VDO, so it's possible in a future addition

Swen

@ronan-a did you test some linstor vars like:
DrbdOptions/auto-diskful': Makes a resource diskful if it was continuously diskless primary for X minutes
'DrbdOptions/auto-diskful-allow-cleanup': Allows this resource to be cleaned up after toggle-disk + resync is finished

Thx for your feedback!

ronan-a

@Swen I suppose that can work with our driver. Unfortunately I haven't tested it.
It can be useful to use it, however we would have to see what impact it has on the DRBD network: for example in a bad case where we would have a chain of diskless VHDs suddenly activated on a host

furyflash777

@olivierlambert
Hi,

is it possible to create more then one linstor SR in pool?

I have this error:
Error code: SR_BACKEND_FAILURE_5006
Error parameters: , LINSTOR SR creation error [opterr=LINSTOR SR must be unique in a pool],

Also, is it possible to have hybrid volume ssd+hdd (cache/autotiring) ?

ronan-a

@furyflash777 You can only use one LINSTOR SR per pool due to a limitation to share the DRBD volume database (and to start the LINSTOR controller). Why do you want many SRs?

furyflash777

@ronan-a

hosts previous was used with VMware VSAN,
I have nvme and HDD disks in the same hosts.

I am new in LINSTOR/DRBD/XOSTOR.

What will be better, use LVM on top of mdm software raid or not?

If a disk fails on one of the servers, will there be an automatic failover to the remaining replica?
Will there be a break in this case?
Will it start writing a new replica to the remaining host?

ronan-a

@furyflash777 I don't recommend mixing HDDs and SSDs with our driver.

Because the replication is managed by LINSTOR, try to not use RAID. A LINSTOR replication of 3 is robust, so if you have many disks on each machine, you can aggregate them into a linear volume.

If a disk fails on one of the servers, will there be an automatic failover to the remaining replica?

As long as there is no split brain, or data corruption, you can automatically use a copy of a VDI.

Will it start writing a new replica to the remaining host?

It depends on the used policy but yes it is possible.

learningdaily

@ronan-a - I've been lurking on this Forum Subject for too long, and I've finally implemented the scripts across three of my hosts, and also added the "Storage" network modifications explained by @Swen and it is working beautifully. Failover is handled by XCP-ng bonded networking if a switch fails, hosts can reboot without any loss in speed or data.

You may recall several years ago I was interested in seeing CEPH implemented natively, but your LINSTOR implementation is so much simpler to manage. Thanks and keep up the good work.