卷Snapshot自动删除
适用场景
- Data ONTAP 8
- ONTAP 9
问题描述
即使当前已将快照保留时间设置为30天、卷快照也会自动删除。
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Snapshot autodelete settings for AUHVSNA1_SHARED:
state=on
commitment=try
trigger=snap_reserve
target_free_space=10%
delete_order=oldest_first
defer_delete=user_created
prefix=(not specified)
destroy_list=none =========================================
00000011.0010da6a 1b4cc5ac Tue Nov 25 2014 00:56:12 11:00 [wafl.volume.snap.autoDelete:info] Deleting snapshot 'weekly.0' in volume 'AUHVSNA1_SHARED' to recover storage
00000011.0010da6c 1b4cc63c Tue Nov 25 2014 00:56:27 11:00 [wafl.volume.snap.autoDelete:info] Deleting snapshot 'hourly.4' in volume 'AUHVSNA1_SHARED' to recover storage
00000011.0010da6e 1b4cc6d1 Tue Nov 25 2014 00:56:42 11:00 [wafl.volume.snap.autoDelete:info] Deleting snapshot 'hourly.3' in volume 'AUHVSNA1_SHARED' to recover storage
00000011.0010da70 1b4cc758 Tue Nov 25 2014 00:56:55 11:00 [wafl.volume.snap.autoDelete:info] Deleting snapshot 'hourly.1' in volume 'AUHVSNA1_SHARED' to recover storage
00000011.0010da72 1b4cc7f1 Tue Nov 25 2014 00:57:11 11:00 [wafl.volume.snap.autoDelete:info] Deleting snapshot 'hourly.0' in volume 'AUHVSNA1_SHARED' to recover storage
00000011.0010da74 1b4cc888 Tue Nov 25 2014 00:57:26 11:00 [wafl.volume.snap.autoDelete:info] Deleting snapshot 'nightly.0' in volume 'AUHVSNA1_SHARED' to recover storage
00000011.0010da76 1b4cc937 Tue Nov 25 2014 00:57:43 11:00 [wafl.volume.snap.autoDelete:info] Deleting snapshot 'Dont_Delete_INC0752286' in volume 'AUHVSNA1_SHARED' to recover storage
00000011.0010da79 1b4cc9ab Tue Nov 25 2014 00:57:55 11:00 [disk.healthTrigger:warning] Disk 3a.42 received NHT health trigger (0x1 0xb 0x5d 0x5)
00000011.0010da7a 1b4cc9e9 Tue Nov 25 2014 00:58:01 11:00 [wafl.volume.snap.autoDelete:info] Deleting snapshot 'Snapshot_4:45_24_11_2014' in volume 'AUHVSNA1_SHARED' to recover storage
00000011.0010da7c 1b4ccaa3 Tue Nov 25 2014 00:58:20 11:00 [wafl.volume.snap.autoDelete:info] Deleting snapshot 'Manual_snapshot' in volume 'AUHVSNA1_SHARED' to recover storage
As you can see here, On Nov 23, the volume /vol/AUHVSNA1_SHARED/ was at 96% capacity. Something happened between Nov 23, and Nov 25 that pushed that volume to its capacity and snapshots were deleted on Nov 25 to save the volume.
Filesystem kbytes used avail capacity Mounted on
Nov 23
/vol/AUHVSNA1_SHARED/ 5653468812 5424660856 228807956 96% /vol/AUHVSNA1_SHARED/
/vol/AUHVSNA1_SHARED/.snapshot 115376912 87988840 27388072 76% /vol/AUHVSNA1_SHARED/.snapshot
Nov 25
/vol/AUHVSNA1_SHARED/ 5858989708 5452568432 406421276 93% /vol/AUHVSNA1_SHARED/
/vol/AUHVSNA1_SHARED/.snapshot 119571216 2969476 116601740 2% /vol/AUHVSNA1_SHARED/.snapshot
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根据选项的要求、最早的快照会首先被删除、但为了使卷保持活动状态、它会因空间问题而不断删除快照、即卷的容量为96%、空间用尽、快照会一直删除、直到空间足够。
此时发生了一些将卷推入容量的情况、所有快照均已删除。如果卷空间允许、删除过程可能会在一个快照处停止；但是、卷空间不允许。
此外 target_free_space 、设置为10%、请参见 自动删除Snapshot副target_free_space本：确定何时停止删除Snapshot副本。target_free_space 此值为卷的一定百分比。例如、如果指定20、则会删除Snapshot副本、直到卷的20%可用空间为止。
通常做法 target_free_space 是、指定比自动删除阈值低2%的值、以避免不必要地删除Snapshot副本。