Re: To LVM or not to LVM?

On 2019/05/07 15:28, Rich J wrote:

> Migrating from AIX to OL7 (x86-64) under VMware with an all-flash SAN, and I'm planning out the logical volumes for database filesystems (non-ASM). I'm now questioning whether or not to use LVM, even for filesystems. If I need to add datafiles without LVM, the Storage Manager adds a new virtual disk to the server, and I create a new mountpoint and set security on it. Easy.
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> In AIX with XIV storage, there was a minimum ~17GB allocation per LUN, so there was space savings in using LVM to group together small control files, redo logs, etc. Not being a vSphere person, I don't know if this is the case there as well.
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> Any opponents/proponents for/against LVM for Oracle database virtual servers?

Thanks for the responses! I guess I'm wondering why one would use LVM for Oracle datafiles. We're currently using AIX's LVM and it's fine. I use LVM on OL6 at home because I have two mountpoints on my RAID set, and LVM makes it a breeze to only expand which ever one I need to and by how much I want.

But for Oracle datafiles, why LVM? It seems like unnecessary overhead, or I just can't think of a scenario where it would be beneficial. Without LVM, I get a 500GB virtual disk and I create a single partition on it, add XFS, and create a mountpoint for it. When I need more than 15 32GB datafiles, I get another 500GB virtual disk. Rinse. Repeat. LVM can certainly do that, too, but with more overhead, and I can't see any advantage to using it for this specific situation.

What am I missing? (besides caffeine) I'm a big fan of the flexibility of LVM, but I want to understand why I should use it here.

Thanks again!
Rich

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