Hi, I'm using a ~4 year old laptop, 4 cores (+4 HT), 32 GB RAM, Crucial mSATA SSD and don't notice neither the snapshotting nor the deletion of snapshots nor the transferring at all (been doing this for years now). I'm running kernel 5.3 now, but have also been on 5.0 some time ago (but I'm on Gentoo, not Ubuntu). So I'd say this is not normal. The first thing you'd need to check is when exactly it happens - btrbk logs the steps it is doing. Does it happen during the snapshotting, transferring, or deletion of snapshots? Anything in the kernel log? Did you run a deduplication tool on the BTRFS volumes, or use quotas? These are the only things which come to my mind which can cause high CPU load here (but in any case, nothing should "block"). Cheers, Oliver Am 20.11.19 um 17:36 schrieb Christian Pernegger: > Hello, > > I've decided to go with a snapshot-based backup solution for our new > Linux desktops -- thank you for the timely thread --, namely btrbk. > A couple of subvolumes for different stuff, with hourly snapshots that > regularly go to another machine. Brilliant in theory, less so in > practice, because every time btrbk runs, the box'll freeze for a few > seconds, as in, Firefox and LibreOffice, for instance, become entirely > unresponsive, games hang and so on. (AFAICT, all it does is snapshot > each subvolume and delete ones that are out of the retention period.) > > I'm aware that having many snapshots can impact performance of some > operations, but I didn't think that "many" <= 200, "impact" = stop > dead and "some operations" = light desktop use. These are decently > specced, after all (Zen 2 8/12 core, 32 GB RAM, Samsung 970 Evo Plus). > What I'm asking is, is this to be expected, does it just need tuning, > is the hardware buggy, the kernel version (Ubuntu 18.04.3 HWE, their > 5.0 series) a stinker, something else awry ...? > > Cheers, > C. >
