[LU-3015] A typo in udmu_objs_count_estimate() causing overly conservative os_ffree values Created: 22/Mar/13 Updated: 15/Oct/13 Resolved: 31/May/13 |
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| Status: | Resolved |
| Project: | Lustre |
| Component/s: | None |
| Affects Version/s: | Lustre 2.4.0 |
| Fix Version/s: | Lustre 2.4.1, Lustre 2.5.0 |
| Type: | Bug | Priority: | Major |
| Reporter: | Li Wei (Inactive) | Assignee: | Li Wei (Inactive) |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| Severity: | 3 |
| Rank (Obsolete): | 7336 |
| Description |
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In this hunk from udmu_objs_count_estimate(): est_refdblocks = (refdbytes >> SPA_MAXBLOCKSHIFT) +
(OSD_DNODE_EST_COUNT << OSD_DNODE_EST_BLKSHIFT);
est_usedobjs = usedobjs + OSD_DNODE_EST_COUNT;
OSD_DNODE_EST_COUNT should be right-shifted, not left-shifted. This typo leads to a larger-than-actual dnode size estimation, which further causes overly conservative os_ffree (number of available objects) values, especially for MDTs. |
| Comments |
| Comment by Li Wei (Inactive) [ 22/Mar/13 ] |
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Current os_ffree values for "empty" 1 GB ZFS-based MDT and OSTs: [root@linux tests]# df -h Filesystem Size Used Avail Use% Mounted on [...] lustre-mdt1/mdt1 929M 3.0M 924M 1% /mnt/mds1 lustre-ost1/ost1 929M 1.3M 926M 1% /mnt/ost1 lustre-ost2/ost2 929M 1.3M 926M 1% /mnt/ost2 linux@tcp:/lustre 1.9G 2.5M 1.9G 1% /mnt/lustre [root@linux tests]# df -i Filesystem Inodes IUsed IFree IUse% Mounted on [...] lustre-mdt1/mdt1 7583 178 7405 3% /mnt/mds1 lustre-ost1/ost1 7631 212 7419 3% /mnt/ost1 lustre-ost2/ost2 7631 212 7419 3% /mnt/ost2 linux@tcp:/lustre 7583 178 7405 3% /mnt/lustre With the typo fixed: [root@linux tests]# df -h Filesystem Size Used Avail Use% Mounted on [...] lustre-mdt1/mdt1 929M 2.9M 924M 1% /mnt/mds1 lustre-ost1/ost1 929M 1.3M 926M 1% /mnt/ost1 lustre-ost2/ost2 929M 1.3M 926M 1% /mnt/ost2 linux@tcp:/lustre 1.9G 2.5M 1.9G 1% /mnt/lustre [root@linux tests]# df -i Filesystem Inodes IUsed IFree IUse% Mounted on [...] lustre-mdt1/mdt1 161966 178 161788 1% /mnt/mds1 lustre-ost1/ost1 223825 212 223613 1% /mnt/ost1 lustre-ost2/ost2 223825 212 223613 1% /mnt/ost2 linux@tcp:/lustre 161966 178 161788 1% /mnt/lustre |
| Comment by Li Wei (Inactive) [ 22/Mar/13 ] |
| Comment by Jodi Levi (Inactive) [ 31/May/13 ] |
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Patch landed to master. Let me know if more patches are needed and I will reopen this ticket. |