On Thu, 4 Jan 2018, Igor Fedotov wrote: > Additional issue with the disk usage statistics I've just realized is that > BlueStore's statfs call reports total disk space as > > block device total space + DB device total space > > while available space is measured as > > block device's free space + bluefs free space at block device - > bluestore_bluefs_free param > > > This results in higher used space value (as available space at DB device > isn't taken into account) and odd results when cluster is (almost) empty. Isn't "bluefs free space at block device" the same as the db device free? (Actually, bluefs may include part of main device too, but that would also be reported as part of bluefs free space.) sage > IMO we shouldn't use DB device for total space calculation. > > Sage, what do you think? > > Thanks, > > Igor > > > > On 12/26/2017 6:25 AM, Zhi Zhang wrote: > > Hi, > > > > We recently started to test bluestore with huge amount of small files > > (only dozens of bytes per file). We have 22 OSDs in a test cluster > > using ceph-12.2.1 with 2 replicas and each OSD disk is 2TB size. After > > we wrote about 150 million files through cephfs, we found each OSD > > disk usage reported by "ceph osd df" was more than 40%, which meant > > more than 800GB was used for each disk, but the actual total file size > > was only about 5.2 GB, which was reported by "ceph df" and also > > calculated by ourselves. > > > > The test is ongoing. I wonder whether the cluster would report OSD > > full after we wrote about 300 million files, however the actual total > > file size would be far far less than the disk usage. I will update the > > result when the test is done. > > > > My question is, whether the disk usage statistics in bluestore is > > inaccurate, or the padding, alignment stuff or something else in > > bluestore wastes the disk space? > > > > Thanks! > > > > $ ceph osd df > > ID CLASS WEIGHT REWEIGHT SIZE USE AVAIL %USE VAR PGS > > 0 hdd 1.49728 1.00000 1862G 853G 1009G 45.82 1.00 110 > > 1 hdd 1.69193 1.00000 1862G 807G 1054G 43.37 0.94 105 > > 2 hdd 1.81929 1.00000 1862G 811G 1051G 43.57 0.95 116 > > 3 hdd 2.00700 1.00000 1862G 839G 1023G 45.04 0.98 122 > > 4 hdd 2.06334 1.00000 1862G 886G 976G 47.58 1.03 130 > > 5 hdd 1.99051 1.00000 1862G 856G 1006G 45.95 1.00 118 > > 6 hdd 1.67519 1.00000 1862G 881G 981G 47.32 1.03 114 > > 7 hdd 1.81929 1.00000 1862G 874G 988G 46.94 1.02 120 > > 8 hdd 2.08881 1.00000 1862G 885G 976G 47.56 1.03 130 > > 9 hdd 1.64265 1.00000 1862G 852G 1010G 45.78 0.99 106 > > 10 hdd 1.81929 1.00000 1862G 873G 989G 46.88 1.02 109 > > 11 hdd 2.20041 1.00000 1862G 915G 947G 49.13 1.07 131 > > 12 hdd 1.45694 1.00000 1862G 874G 988G 46.94 1.02 110 > > 13 hdd 2.03847 1.00000 1862G 821G 1041G 44.08 0.96 113 > > 14 hdd 1.53812 1.00000 1862G 810G 1052G 43.50 0.95 112 > > 15 hdd 1.52914 1.00000 1862G 874G 988G 46.94 1.02 111 > > 16 hdd 1.99176 1.00000 1862G 810G 1052G 43.51 0.95 114 > > 17 hdd 1.81929 1.00000 1862G 841G 1021G 45.16 0.98 119 > > 18 hdd 1.70901 1.00000 1862G 831G 1031G 44.61 0.97 113 > > 19 hdd 1.67519 1.00000 1862G 875G 987G 47.02 1.02 115 > > 20 hdd 2.03847 1.00000 1862G 864G 998G 46.39 1.01 115 > > 21 hdd 2.18794 1.00000 1862G 920G 942G 49.39 1.07 127 > > TOTAL 40984G 18861G 22122G 46.02 > > > > $ ceph df > > GLOBAL: > > SIZE AVAIL RAW USED %RAW USED > > 40984G 22122G 18861G 46.02 > > POOLS: > > NAME ID USED %USED MAX AVAIL OBJECTS > > cephfs_metadata 5 160M 0 6964G 77342 > > cephfs_data 6 5193M 0.04 6964G 151292669 > > > > > > Regards, > > Zhi Zhang (David) > > Contact: zhang.david2011@xxxxxxxxx > > zhangz.david@xxxxxxxxxxx > > -- > > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > > the body of a message to majordomo@xxxxxxxxxxxxxxx > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > >
