On Fri, Apr 30, 2021 at 6:16 PM Roger Heflin <[email protected]> wrote:
> I don't know why but the spinning disk is being crushed. > Well, a little googling after my post it appears the database is LMDB, which is a COW db. So I can see how a COW DB on top of a COW FS may be a problem, but I have marked the directory nodatacow... $ lsattr ~/.bitmonero/lmdb -------------------- /home/richard/.bitmonero/lmdb/lock.mdb ---------------C---- /home/richard/.bitmonero/lmdb/data.mdb if you divide the mb/sec by the reads you get around 4k per read > (that is about as bad as you could do). > if you multiply the reads/sec * r_await you get all of the time accounted > for. > > And since each read is taking around 8-10ms (around the disks seek > time for a new track) then each block being read is not being cached > in the disk hence probably not on the same track that the disk just > read or as the disk recently read and still has in its cache. If the > file you are rsyncing was written slowly or quickly with a number of > other IO's happening between each io then that increases the chances > of the file being massively fragmented and act like this. > > Is this a single file and this single rsync is the only thing running? > I down know the inner workings of the client, but it is a single file as seen above. And what disk are you syncing to/from? And how was the file that > you are rsyncing created? I have seen a DB do this (in a sequential > backup) and that file was created in such a way that for the most part > no 2 blocks were next to each other on a disk. I believe the average > blocksize for that file was 5.1k. the filefrag command will show > file fragments on some filesystems. There may be different commands > needed depending on what filesystem the file comes from. > $ filefrag ~/.bitmonero/lmdb/data.mdb /home/richard/.bitmonero/lmdb/data.mdb: 388217 extents found Thanks, Richard
_______________________________________________ users mailing list -- [email protected] To unsubscribe send an email to [email protected] Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/[email protected] Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure
