Can I use RHEL5 with thin-provisioned storage?

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I want to use RHEL server 5 with thin-provisioned LUNs on IBM Storwize V7000. I don't need to release unused blocks, just need to have storage growing up as data grows up. Assuming the disk storage is generaly supported for use with RHEL5, can I use the thin-provisioning feature? Is it safe for data? As I understand the thin-provisioning problems, it should be. But I have not found any confirming document/article.


The primary value of the OS being aware of the underlying storage being thin is that the OS can be a "good citizen" and tell the storage subsystem to return blocks to its free pool when the OS no longer has data on those blocks. Absent a plugin that allows this kind of lower-level communications between the OS and the storage, the OS will simply treat the storage as though it were standard "thick" (pre-allocated) storage. The resulting primary "danger" of thin-provisioned storage is that the storage layer is lying to the OSes that reference the storage. The host OS may think it has 36GB free when, in actuality, it has zero free. When it goes to make a write, the underlying storage will return an unexpected failure. Depending on what's attempting the write, this could simply result in a transaction failure up through corruption of data or even a system crash.

To summarize, "yes, you can use thin provisioned storage with RHEL 5". You just need to be aware of the missing optimizations and the general risks of thin-provisioned storage.

I'm in complete agreement with Tom. I've used thin-provisioned storage with RHEL5 on Netapp-based storage, and it worked reasonably well. If you start doing this in production at a reasonable amount of scale, you will want to establish a practice of monitoring disk usage on these VMs and your storage devices to ensure you are adequately accounting for storage requirements.

Hello Karol,
I would be sure to follow IBM's recommendations for tuning. (search for "rhel 5 IBM Storwize V7000"