Short answer: no and no. Long:
1. having size = 2 is safe *if you also keep min_size at 2*. But that's not highly available so you usually don't want this. min_size = 1 (or reducing min size on an ec pool) is basically a guarantee to lose at least some data/writes in the long run. 2. It's no longer as important as it used to be yes. We typically increase the interval to a month instead of the default week with bluestore. But a properly tuned scrubbing configuration has a neglible overhead and it can give you some confidence about the integrity of data that is rarely accessed. Paul Am So., 23. Sep. 2018 um 08:49 Uhr schrieb jython.li <[email protected]>: > > "when using BlueStore, Ceph can ensure data integrity by conducting a > cyclical redundancy check (CRC) on write operations; then, store the CRC > value in the block database. On read operations, Ceph can retrieve the CRC > value from the block database and compare it with the generated CRC of the > retrieved data to ensure data integrity instantly" > from > https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/3/html-single/architecture_guide/#ensuring_data_integrity > > As mentioned above, BlueStore calculates, stores, and verifies checksums for > all data and metadata it stores, then, my question are： > 1. In bulestore, is it safe enough to use two copies in the production > environment? > > In the filestore, there is no CRC, if you use two copies, there will be brain > splitting. For example, when ceph checks that the data between the two copies > is inconsistent, then ceph will not know which copy data is correct. > But in BlueStore, all write data will have CRC, then even if there is > inconsistency between the two copies, ceph will know which copy is correct > (using the CRC value saved in block database) > > > 2. Similarly, can we turn off deep-scrub at this time? > > > > > _______________________________________________ > ceph-users mailing list > [email protected] > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Paul Emmerich Looking for help with your Ceph cluster? Contact us at https://croit.io croit GmbH Freseniusstr. 31h 81247 München www.croit.io Tel: +49 89 1896585 90 _______________________________________________ ceph-users mailing list [email protected] http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
