Hello Jake, do you have any latency requirements that you do require the DB/WAL at all? If not, CephFS with EC on SATA HDD works quite well as long as you have the metadata on a separate ssd pool.
-- Martin Verges Managing director Mobile: +49 174 9335695 E-Mail: martin.ver...@croit.io Chat: https://t.me/MartinVerges croit GmbH, Freseniusstr. 31h, 81247 Munich CEO: Martin Verges - VAT-ID: DE310638492 Com. register: Amtsgericht Munich HRB 231263 Web: https://croit.io YouTube: https://goo.gl/PGE1Bx Am Di., 28. Mai 2019 um 15:13 Uhr schrieb Jake Grimmett < j...@mrc-lmb.cam.ac.uk>: > Dear All, > > Quick question regarding SSD sizing for a DB/WAL... > > I understand 4% is generally recommended for a DB/WAL. > > Does this 4% continue for "large" 12TB drives, or can we economise and > use a smaller DB/WAL? > > Ideally I'd fit a smaller drive providing a 266GB DB/WAL per 12TB OSD, > rather than 480GB. i.e. 2.2% rather than 4%. > > Will "bad things" happen as the OSD fills with a smaller DB/WAL? > > By the way the cluster will mainly be providing CephFS, fairly large > files, and will use erasure encoding. > > many thanks for any advice, > > Jake > > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
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