Hi, I am a bit confused by the documentation as it seems to say that, when using bluestore, there is no need to put the journaling on a faster storage when creating OSD
https://docs.ceph.com/en/reef/rados/configuration/osd-config-ref/ <https://can01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.ceph.com%2Fen%2Freef%2Frados%2Fconfiguration%2Fosd-config-ref%2F&data=05%7C02%7CSteven.Vacaroaia%40awavesemi.com%7C4e93610d4e61495d79b808dd9d2e1408%7Ca7b6f886db244de6b0f422ed9c9c6dfd%7C0%7C0%7C638839543798023056%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=KmH7lfzeuPG0JkJOjuDvnge11qIuKZXH8pd9qDNGX%2F4%3D&reserved=0> But then I found this : “… BlueStore is deployed across one or two additional devices: - A *write-ahead log (WAL) device* (identified as block.wal in the data directory) can be used to separate out BlueStore’s internal journal or write-ahead log. Using a WAL device is advantageous only if the WAL device is faster than the primary device (for example, if the WAL device is an SSD and the primary device is an HDD). - A *DB device* (identified as block.db in the data directory) can be used to store BlueStore’s internal metadata. BlueStore (or more precisely, the embedded RocksDB) will put as much metadata as it can on the DB device in order to improve performance. If the DB device becomes full, metadata will spill back onto the primary device (where it would have been located in the absence of the DB device). Again, it is advantageous to provision a DB device only if it is faster than the primary device. …” Is it still recommended to put WAL and DB on a faster disk , right ? How can this be done with cephadm .? Is there a documented procedure for fixing this if it was not done from the beginning ? Many thanks Steven _______________________________________________ ceph-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
