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0e1f616
(Get the code!)
Description of problem:
Defaults to using cache with an LVM backed storage. The use of caching with raw partitions (LVM) results in significantly lower performance than no cache at all.
How reproducible:
Always
Steps to Reproduce:
1. Create a new VM using LVM backed storage
Actual results:
Cache is enabled for the VM's disks residing within LVM.
Expected results:
Cache should be disabled for disks residing within LVM.
Additional info:
http://
Specifically:
QEMU also supports a wide variety of caching modes. Writeback is useful for testing but does not offer storage guarantees. Writethrough (the default) is safer, and relies on the host cache. If you're using raw volumes or partitions, it is best to avoid the cache completely, which reduces data copies and bus traffic:
qemu -drive file=/dev/
This has also been reported with Ubuntu at: https:/