Ignore sysfs file read errors

[harshavardhana]

No description provided.

[Praveenrajmani]

we can set false to the readFirstLine function here -

directpv/pkg/device/sysfs_linux.go

Line 75 in c0ae169

s, err := readFirstLine("/sys/class/block/"+name+"/size", true)

[balamurugana]

we can set false to the readFirstLine function here -

directpv/pkg/device/sysfs_linux.go

Line 75 in c0ae169

s, err := readFirstLine("/sys/class/block/"+name+"/size", true)

@harshavardhana @Praveenrajmani Do you guys see sysfs devices with no size entry?

[Praveenrajmani]

yes @balamurugana

portworx volumes are missing this

[harshavardhana]

we can set false to the readFirstLine function here -

directpv/pkg/device/sysfs_linux.go

Line 75 in c0ae169

s, err := readFirstLine("/sys/class/block/"+name+"/size", true)

@harshavardhana @Praveenrajmani Do you guys see sysfs devices with no size entry?

Yes portworx devices seems to have it missing, an another CSI product.

[harshavardhana]

we can set false to the readFirstLine function here -

directpv/pkg/device/sysfs_linux.go

Line 75 in c0ae169

s, err := readFirstLine("/sys/class/block/"+name+"/size", true)

We can simply ignore all devices that do not comply with what we want. I am not big fan of failing pods with no easy to understand errors.

Unless we want to log why we are ignoring the drives? That is okay too.

[balamurugana]

@harshavardhana You could pass false at https://github.com/minio/directpv/blob/master/pkg/device/sysfs_linux.go#L75 which fixes the issue.

[harshavardhana]

@harshavardhana You could pass false at https://github.com/minio/directpv/blob/master/pkg/device/sysfs_linux.go#L75 which fixes the issue.

No @balamurugana that is not a complete fix. We should ignore all devices that do not comply with Disk metadata that we want.

It is not just about /size there are other files that may be missing. There is no document that indicates that these files "must" be present or they are mandatory.

The current PR simply addresses this more comprehensively. For example, portworx has a couple of other files missing as well. If we only fixed /size alone is not sufficient.

IMO we shouldn't crash our pods unnecessarily. We should work when we have other good drives we can manage.

This is a support nightmare and also a bad POC experience. We should be able to deploy DirectPV without @balamurugana or @Praveenrajmani's involvement.