[sheepdog-users] monitor cluster to avoid corruption

[Valerio Pachera]

*If it happens to write till the end of the cluster, the disk get corrupted*
  collie vdi check test
  Failed to read, No object found

I've been testing with only 1 vdi and 1 guest.
If we have more disks, they might get corrupted as well.

Correct me if I'm wrong, but the only thing it can be done is to
delete the vdi disk.

To monitor when the cluster is getting full, we have
  collie node info

It's pretty easy if we have nodes all with the same amount of space,
we just have to look at the 'Total' percentage or any of the disk.
It gets more difficult when we have different node sizes.

Here is an example, after I've been writing 512M (formated with 2 copies)
---
collie  node info
Id      Size    Used    Use%
 0      982 MB  196 MB   19%
 1      982 MB  160 MB   16%
 2      982 MB  204 MB   20%
 3      10.0 GB 528 MB    5%
Total   13 GB   1.1 GB    8%
Total virtual image size        10 GB
---

And here is the same cluster after I've been writing data till filling
up all the available space.
---
fino in fondo
collie  node info
Id      Size    Used    Use%
 0      982 MB  980 MB   99%
 1      982 MB  796 MB   81%
 2      982 MB  952 MB   96%
 3      10.0 GB 2.5 GB   25%
Total   13 GB   5.2 GB   40%
Total virtual image size        10 GB
---

*Obviously we can't look at the 'Total' percentage to understand when
the cluster is getting full.*
Think of a different scenario with several different node sizes (1T,
500G, 2T, 750G....).
I bet you to find out the total amount of available space and, more
important, the total free space (percentage) of the cluster.

May it be possible to print the 'Total relative available space ' and
the respective percentage?
The actual 'Total' is just the sum of the devices.
If not, may you please tell me how to calculate it?

*Is it going to be possible to avoid disk corruption?*