On Thu, Jul 26, 2018 at 2:58 AM, 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 > > Hello Len, I just tried your volume create test on a machine with Gold 6154 CPUs and 768G of RAM running 20180629T124501Z and it was quick: # time zfs create -V 10G zones/test real 0m0.155s user 0m0.003s sys 0m0.005s Is there anything unusual in your pool configuration? I have a stripe of 5 SAS drive mirrors and a couple of Toshiba PX05S SAS SSD logs. Cheers, Ian. ------------------------------------------- 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
