On 12/08/2016 08:53 AM, Ian Pilcher wrote:
Running cache_repair against the metadata device gives me this error: transaction_manager::new_block() couldn't allocate new block I strongly suspect that my metadata device is too small. It was sized with the algorithm that I posted to this list about a year ago: https://www.redhat.com/archives/dm-devel/2015-November/msg00221.html Looking at the source code for cache_metadata_size, I see that it adds additional space for "hints", which the old algorithm didn't account for.
I finally got around to testing my hypothesis, and I can confirm that the size of the metadata device is indeed the problem. With a larger metadata device, cache_repair succeeds, and I am able to assemble the cache device. So I obviously need to change the formula that I'm using to calculate the size of the metadata device, which begs the question ... what is the CANONICAL formula for doing this? lvmcache(7) says, "The size of this LV should be 1000 times smaller than the cache data LV, with a minimum size of 8MiB." But this is definitely *not* the formula used by cache_metadata_size, and cache_metadata_size seems to assume that hints will never be larger than 4 bytes. -- ======================================================================== Ian Pilcher arequipeno@xxxxxxxxx -------- "I grew up before Mark Zuckerberg invented friendship" -------- ======================================================================== -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
