Using LVM, what are the performance implications of using thinpool on an logical volume?
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Tom Hale
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It depends of type of drive below it. When that's a ssd drive (where random access is simmilar to linear access) - there will be no difference. When using snapshot - there can be some performance boost. But - if there is a magnetic drive(where random access is much slower than linear access) - there will be some performance loss because of jumps to different areas of disk.
undefine
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What about the lookup of what blocks are where on the disk? – Tom Hale Jan 02 '17 at 04:58
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1that's in metadata - and for "my" cases - metadata are small, so they're fully cached. – undefine Jan 02 '17 at 08:27
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In normal operation, none. When snapshots are brought into the mix, thin provisioned LVs perform a lot better.
womble
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1`In normal operation, none` -- How can this be true? There is an additional lookup of the block map in the meta volume for starters. How (metrics, measures) does thin-provisioning make performance `a lot better` with snapshots? – Tom Hale Oct 31 '16 at 11:11
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If you have a more specific question to ask, you should ask that as a new question, rather than try to expand the scope of your question in a comment on an answer. – womble Oct 31 '16 at 20:59
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4I'm not trying to increase the scope of my question. I'm simply asking for some evidence for your assertions. – Tom Hale Nov 01 '16 at 08:47