On 20 October 2015 at 19:33, Joe Thornber <thornber@xxxxxxxxxx> wrote: > On Tue, Oct 20, 2015 at 11:51:07AM +0500, Bogdan Vasiliev wrote: >> Hello, >> >> I have dm-cache configuraion with SSD in writeback mode. On every boot >> an entire cache resyncs to an origin device, even if it was clean >> before on shutdown. It takes time and full bandwidth of an origin >> device. >> >> Is there reason for this behavior or is it a bug? Why we do not trust >> a cache metadata? > > If the cache is not taken down cleanly then dm-cache has to assume > every block is dirty. Make sure your shutdown scripts are removing > the cache device. How I do it: # umount /dev/mapper/storage-data # lvs -o lv_name, cache_dirty_blocks LV CacheDirtyBlocks data 0 # sync # dmsetup remove_all # vgchange -ay 1 logical volume(s) in volume group "storage" now active # lvs -o lv_name, cache_dirty_blocks LV CacheDirtyBlocks data 122657 Volume was clearly removed without dirty cahe blocks, re-initialized and began full re-sync to the origin. Is this normal behavior? >> My configuration details, if necessary: >> storage-cache_cdata:0 41943040 linear >> storage-cache_cmeta: 0 1048576 linear >> storage-data: 0 1953513472 cache 8 989/131072 128 173945/327680 610488 >> 20046 574861 3817439 0 0 0 1 writeback 2 migration_threshold 2048 mq >> 10 random_threshold 4 sequential_threshold 512 >> discard_promote_adjustment 1 read_promote_adjustment 4 >> write_promote_adjustment 8 rw - >> storage-data_corig: 0 1953513472 linear -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
