Maybe worth to mention, because it caught me by surprise: Ubuntu creates a swap file (/swap.img) if you do not specify a swap partition (check /etc/fstab). Cheers Boris Am Mi., 15. März 2023 um 22:11 Uhr schrieb Anthony D'Atri < aad@xxxxxxxxxxxxxx>: > > With CentOS/Rocky 7-8 I’ve observed unexpected usage of swap when there is > plenty of physmem available. > > Swap IMHO is a relic of a time when RAM capacities were lower and much > more expensive. > > In years beginning with a 2, and with Ceph explicitly, I assert that swap > should never be enabled during day to day operation. > > The RAM you need depends in part on the media you’re using, and how many > per node, but most likely you can and should disable your swap. > > > > > Hello, > > We have a 6-node ceph cluster, all of them have osd running and 3 of > them (ceph-1 to ceph-3 )also has the ceph-mgr and ceph-mon. Here is the > detailed configuration of each node (swap on ceph-1 to ceph-3 has been > disabled after the alarm): > > > > # ceph-1 free -h > > total used free shared > buff/cache available > > Mem: 187Gi 38Gi 5.4Gi 4.1Gi 143Gi > 142Gi > > Swap: 0B 0B 0B > > # ceph-2 free -h > > total used free shared > buff/cache available > > Mem: 187Gi 49Gi 2.6Gi 4.0Gi 135Gi > 132Gi > > Swap: 0B 0B 0B > > # ceph-3 free -h > > total used free shared > buff/cache available > > Mem: 187Gi 37Gi 4.6Gi 4.0Gi 145Gi > 144Gi > > Swap: 0B 0B 0B > > # ceph-4 free -h > > total used free shared > buff/cache available > > Mem: 251Gi 31Gi 8.3Gi 231Mi 211Gi > 217Gi > > Swap: 124Gi 3.8Gi 121Gi > > # ceph-5 free -h > > total used free shared > buff/cache available > > Mem: 251Gi 32Gi 14Gi 135Mi 204Gi > 216Gi > > Swap: 124Gi 4.0Gi 121Gi > > # ceph-6 free -h > > total used free shared > buff/cache available > > Mem: 251Gi 30Gi 16Gi 145Mi 204Gi > 218Gi > > Swap: 124Gi 4.0Gi 121Gi > > > > We have configured swap space on all of them, for ceph-mgr nodes, we > have 8G swap space and 128G swap configured for osd nodes, and our zabbix > has monitored a swap over 50% usage for ceph-1 to ceph-3, but our available > space are still around 140G against the total 187G. Just wondering whether > the swap space is necessary when we have lots of memory available? > > > > Thanks very much for your answering. > > _______________________________________________ > > ceph-users mailing list -- ceph-users@xxxxxxx > > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ > 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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