Hello In my CEPH Nautilus cluster, some OSDs have unexpectedly gone offline, despite all SSD disks appearing to be active on the node. What might be the cause of this issue? #ceph osd tree [showing disk for ceph6 status] -11 19.20854 host ceph6 10 ssd 1.74609 osd.10 down 0 1.00000 35 ssd 1.74609 osd.35 up 1.00000 1.00000 40 ssd 1.74609 osd.40 down 0 1.00000 45 ssd 1.74609 osd.45 down 0 1.00000 50 ssd 1.74609 osd.50 down 0 1.00000 54 ssd 1.74609 osd.54 up 1.00000 1.00000 58 ssd 1.74609 osd.58 up 1.00000 1.00000 59 ssd 1.74609 osd.59 up 1.00000 1.00000 67 ssd 1.74660 osd.67 up 1.00000 1.00000 68 ssd 1.74660 osd.68 down 0 1.00000 90 ssd 1.74660 osd.90 up 1.00000 1.00000 root@ceph6:~# fdisk -l | grep 1920383410176 Disk /dev/sdb: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sda: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sdd: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sdc: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sdf: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sdg: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sdh: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sdi: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sde: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sdj: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sdk: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Disk /dev/sdl: 1.8 TiB, 1920383410176 bytes, 3750748848 sectors Regards Mosharaf Hossain Manager, Product Development IT Division Bangladesh Export Import Company Ltd. Level-8, SAM Tower, Plot #4, Road #22, Gulshan-1, Dhaka-1212,Bangladesh Tel: +880 9609 000 999, +880 2 5881 5559, Ext: 14191, Fax: +880 2 9895757 Cell: +8801787680828, Email: mosharaf.hossain@bol-online.com, Web: www.bol-online.com <https://www.google.com/url?q=http://www.bol-online.com&sa=D&source=hangouts&ust=1557908951423000&usg=AFQjCNGMxIuHSHsD3qO6y5JddpEZ0S592A>