Thx Tim. I also found this limitation written elsewhere after posting this:
Important! A volume can only be mounted using one access mode at a time, even if it supports many. For example, a GCEPersistentDisk can be mounted as ReadWriteOnce by a single node or ReadOnlyMany by many nodes, but not at the same time. from: https://kubernetes.io/docs/user-guide/persistent-volumes/#gce I'm going to presume this is a fundamental limitation in the underlying infrastructure (GCE/AWS whatever) under GKE and will not change. Rather than looking into NFS or disk cache tuning [its been a long time :P], or diverting this thread I will post a new Q with my root issues that led me here. On Tuesday, 14 February 2017 22:12:31 UTC, Tim Hockin wrote: > PD can mount read-only EVERYWHERE or read-write once. No mixing. The > problem is that every filesystem keeps state in memory, even in > read-only mode. If the on-disk state changes while readers have > cached state you will get corruption. > > On Tue, Feb 14, 2017 at 9:15 AM, <dan.gard...@baddogdown.com> wrote: > > > > Use case: I was hoping to run a k8s Deployment volume mounting a common PD > > as readOnly and then use a single k8s (cron)Job to manage the content of > > the PD. But alas it s not working. Any ideas please, details below ? > > > > GKE: Master & Node versions: 1.5.2 [not using alpha features, hence Job not > > cronJob] > > > > 1. SUCCESS: Mounting a PD xyz as gcePersistentDisk readOnly into a k8s > > deployment running on node-pool 123, all pods can mount the volume. > > > > 2. SUCCESS: Mounting a PD xyz as gcePersistentDisk readWrite into a k8s Job > > running on node-pool 456, the Pod created for the job can mount the volume. > > > > 3. FAIL: Being able to do both #1 & #2 simultaneously. > > > > I was hoping since I've segregated the Deployment & the Job onto different > > nodes that this would work. > > > > -- > > You received this message because you are subscribed to the Google Groups > > "Kubernetes user discussion and Q&A" group. > > To unsubscribe from this group and stop receiving emails from it, send an > > email to kubernetes-users+unsubscr...@googlegroups.com. > > To post to this group, send email to kubernetes-users@googlegroups.com. > > Visit this group at https://groups.google.com/group/kubernetes-users. > > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Kubernetes user discussion and Q&A" group. To unsubscribe from this group and stop receiving emails from it, send an email to kubernetes-users+unsubscr...@googlegroups.com. To post to this group, send email to kubernetes-users@googlegroups.com. Visit this group at https://groups.google.com/group/kubernetes-users. For more options, visit https://groups.google.com/d/optout.
