Hi Samuel, IIRC at least the DB (I am not sure if flash drives use the 1GB WAL) is always located on the same device as the OSD, when it is not configured somewhere else. On SSDs/NVMEs people tend to not separate the DB/WAL on other devices. Cheers Boris Am Mo., 25. Apr. 2022 um 10:09 Uhr schrieb huxiaoyu@xxxxxxxxxxxx < huxiaoyu@xxxxxxxxxxxx>: > Dear Ceph folks, > > When setting up an all flash Ceph cluster with 8 nodes, I am wondering > whether should i disable (or turn off) DB and WAL for SSD based OSDs for > better 8K IO performance. > > Nornally for HDD OSDs, i used to create a 30GB+ partitions on separate > SSDs as DB/WAL for them. For (enterprise level)SSD-based OSDs, one way is > to create a partition on every SSD OSD as DB/WAL, and then use the rest as > the data partition of the OSD. However, I am wondering whether such > operation would improve performance or degrade performance? Since WAL is > just a pure write buffering, it could cause double writes on the same SSD > and thus cause damage to the performance... > > Any comments, suggestions are highly appreciated, > > Samuel > > > > huxiaoyu@xxxxxxxxxxxx > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > -- Die Selbsthilfegruppe "UTF-8-Probleme" trifft sich diesmal abweichend im groüen Saal. _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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