Hi Bogdan, Are the "client failing to respond" messages indicating that you actually exceed the 128 GB ram on your MDS hosts? The MDS servers are not planned to have SSD drives. The storage servers would have HD's and 1 nVME SSD drive that could hold metadata volumes. On Thu, Feb 6, 2020 at 4:11 PM Bogdan Adrian Velica <vbogdan@xxxxxxxxx> wrote: > > Hi, > I am running on 3 MDS servers (1 active and 2 backups and I recommend that) each of 128 GB of RAM (the clients are running ML analysis) and I have about 20 mil inodes loaded in ram. It's working fine except some warnings I have "client X is failing to respond to cache pressure." > Besides that there are no complaints but I thing you would need the 256GB of ram specially if the datasets will increase... just my 2 cents.. > > Will you have SSD ? > > > > On Fri, Feb 7, 2020 at 12:02 AM Matt Larson <larsonmattr@xxxxxxxxx> wrote: >> >> Hi, we are planning out a Ceph storage cluster and were choosing >> between 64GB, 128GB, or even 256GB on metadata servers. We are >> considering having 2 metadata servers overall. >> >> Does going to high levels of RAM possibly yield any performance >> benefits? Is there a size beyond which there are just diminishing >> returns vs cost? >> >> The expected use case would be for a cluster where there might be >> 10-20 concurrent users working on individual datasets of 5TB in size. >> I expect there would be lots of reads of the 5TB datasets matched with >> the creation of hundreds to thousands of smaller files during >> processing of the images. >> >> Thanks! >> -Matt >> >> -- >> Matt Larson, PhD >> Madison, WI 53705 U.S.A. >> _______________________________________________ >> ceph-users mailing list -- ceph-users@xxxxxxx >> To unsubscribe send an email to ceph-users-leave@xxxxxxx -- Matt Larson, PhD Madison, WI 53705 U.S.A. _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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