On Sat, Aug 11, 2018 at 12:44:18AM -0400, Chris Laprise wrote: > On 08/10/2018 03:02 PM, Kelly Dean wrote: > > Has anybody else used both Qubes 3.2 and 4.0 on a system with a HD, not > > SSD? Have you noticed the disk thrashing to be far worse under 4.0? I > > suspect it might have something to do with the new use of LVM combining > > snapshots with thin provisioning. > > > > The problem seems to be triggered by individual qubes doing ordinary bursts > > of disk access, such as loading a program or accessing swap, which would > > normally take just a few seconds on Qubes 3.2, but dom0 then massively > > multiplies that I/O on Qubes 4.0, leading to disk thrashing that drags on > > for minutes at a time, and in some cases, more than an hour. > > > > iotop in dom0 says the thrashing procs are e.g. [21.xvda-0] and > > [21.xvda-1], reading the disk at rates ranging from 10 to 50 MBps (max > > throughput of the disk is about 100). At this rate, for how prolonged the > > thrashing is, it could have read and re-read the entire virtual disk > > multiple times over, so there's something extremely inefficient going on. > > > > Is there any solution other than installing a SSD? I'd prefer not to have > > to add hardware to solve a software performance regression. > > > > I really don't know if LVM or Ext4 have an SSD/HDD mode, but Btrfs does. The > HDD mode avoids some thrashing. > > Also, I remember installing a 4.0 release candidate on an external HDD and > didn't note unusual thrashing at the time. > > > -- > > Chris Laprise, tas...@posteo.net > https://github.com/tasket > https://twitter.com/ttaskett > PGP: BEE2 20C5 356E 764A 73EB 4AB3 1DC4 D106 F07F 1886
I don't recognise this on a somewhat under powered laptop with HDD - definitely not "minutes at a time". Is there something significant about the disks that you cite, or are those just examples? -- You received this message because you are subscribed to the Google Groups "qubes-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to qubes-users+unsubscr...@googlegroups.com. To post to this group, send email to qubes-users@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/qubes-users/20180812141347.obgxvajspbgblmmt%40thirdeyesecurity.org. For more options, visit https://groups.google.com/d/optout.
