Hi I see this commit and the hosts where we see issues have 2 NVMe devs used as slogs if that helps
https://github.com/joyent/illumos-joyent/commit/f78cdc34af236a6199dd9e21376f4a46348c0d56 <https://github.com/joyent/illumos-joyent/commit/f78cdc34af236a6199dd9e21376f4a46348c0d56> Len > On 25 Jul 2018, at 16:58, Len Weincier <[email protected]> wrote: > > Hi > > We a very strange situation trying to upgrade to a newer smartos image where > the disk I/O is *very* slow. > > I have been working through the released images and the last one that works > 100% is 20180329T002644Z > > From 20180412T003259Z onwards, the release with the new zfs features like > spacemaps etc, the hosts become unusable in terms of disk i/o > > In our testing with the lab machine with only 128G ram we see no pathologies. > > Hosts are running ALL SSDs (RAIDZ2), and Intel Gold 6150 x2 processors on an > SMC X11DPH-T board.. > The lab machine with 128GB RAM has exactly the same processors, board, and > SSD-only setup - except for RAM.. > > On a production machine with 768G ram and the newer image for eg zfs create > -V 10G zones/test takes 2 minutes while at the same time iostat is showing > the disks as relatively idle (%b = 10) > > For example inside an ubuntu kvm with postgres we are seeing 40% wait time > for any disk i/o and there are only 2 vm's running, underlying disks > essentially idle. > > Is there anything we can look at to get to the bottom of this as it pretty > critical and affecting our customers > > Any help appreciated > Thanks > Len > > -- > > CloudAfrica > ------------------------------------------- smartos-discuss Archives: https://www.listbox.com/member/archive/184463/=now Modify Your Subscription: https://www.listbox.com/member/?member_id=25769125 Powered by Listbox: https://www.listbox.com
