Dne 14.11.2016 v 16:02 Alexander Pashaliyski napsal(a):
Hi guys, I am in a process of evaluating dm-cache for our backup system. Currently I have an issue when restart the backup server. The server is booting for hours, because of IO load. It seems is triggered a flush from SSD disk (that is used for a cache device) to the raid controllers (they are with slow SATA disks). I have 10 cached logical volumes in *writethrough mode*, each with 2T of data over 2 raid controllers. I use a single SSD disk for the cache. The backup system is with lvm2-2.02.164-1 & kernel 4.4.30. Do you have any ideas why such flush is triggered? In writethrough cache mode we shouldn't have dirty blocks in the cache.
Hi Have you ensured there was proper shutdown ? Cache needs to be properly deactivated - if it's just turned off, all metadata are marked dirty. Regards Zdenek -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
