Re: FreeBSD 13.0 terrible performance in KVM
On 25.04.21 11:15, dashdruid via freebsd-stable wrote: Hello, I have reinstalled it with GPT/ZFS and your right it's much better. Same search taking 3-6 seconds so I have deleted now all my old UFS based FreeBSD images. If the partitioning alone changed something it was probably an alignment problem. These are things you can try: * Create a VM with two virtual disks. * Install a UFS system on the first disk. * Create and mount a UFS on the unpartitioned second disk. * Copy the whole system with tar to the second disk. * Reboot the VM. * Compare performance on both file disks. Maybe your virtual disk backend is is just terrible with unaligned accesses. ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: FreeBSD 13.0 terrible performance in KVM
> Am 24.04.2021 um 15:03 schrieb Jeff Love : > > I'm running 12.2 and 13.0 on KVM using virtio and zfs. I am not having disk > I/O issues. UFS or ZFS does not make a difference for me. ZFS is faster on read due to compression - that’s why back in the XenServer days I didn’t even realize it until somebody complained. It’s just a tad laggy in idle or normal conditions, but any kind of IO brings the system down to a crawl - and that is noticeable. ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: FreeBSD 13.0 terrible performance in KVM
Hello, I have reinstalled it with GPT/ZFS and your right it's much better. Same search taking 3-6 seconds so I have deleted now all my old UFS based FreeBSD images. I wonder how I didn't notice this earlier because I had 12.0, 12.2 base images and now that I retested them they had the exact same issues. I guess after the stuff is loaded into memory it doesn't matter anymore. This must be something related to the virtual disk access. I was not thinking on using ZFS due to the higher memory recommendations, some of these VMs I using them for tiny tasks like DNS server and I don't give them more than 256, 512MB of ram. Also I don't take advantage of snapshotting either since it's a VM and it's either snapshotted or I just have base images and copy them when creating new VMs. Well UFS is on it's way out anyway. ‐‐‐ Original Message ‐‐‐ On Saturday, April 24, 2021 3:03 PM, Jeff Love j...@burgh.net wrote: > I'm running 12.2 and 13.0 on KVM using virtio and zfs. I am not having > disk I/O issues. > Jeff Love > On 4/24/21 5:25 AM, dashdruid via freebsd-stable wrote: > >> Hello List, >> I hope some other folks out there running FreeBSD on KVM as well. I set up a >> base VM while doing so I noticed that the disk operations are very slow. >> Many times I edit a file in vim or try to run a command there is a huge lag. >> I use UFS as the root filesystem. To have something to compare it with I >> have tested it against an OpenBSD 6.6 VM on the same host, same hardware. >> both have 1 vCPU and 1GB of ram, 20GB virtual disk (they are exactly on the >> same physical disk no raid or anything to have a fair comparison). >> Here is an example simple file search time for a non-existent file: >> FreeBSD 13 >> time find / -name cacert.pem >> real 0m30.656s >> user 0m0.516s >> sys 0m3.938s >> Second run even worse >> real 2m38.618s >> user 0m0.711s >> sys 0m6.882s >> While on the OpenBSD VM I get >> time find / -name cacert.pem >> real 0m2.258s >> user 0m0.290s >> sys 0m1.970s >> The amount of data is about the same on both systems but I would not >> consider this a "slight" performance degradation. If the base system is so >> slow then imagine putting Apache and other servers on top of it. Did anyone >> run into this? >> Unless there is a definitive solution I will opt out to using other BSD >> variants. >> freebsd-stable@freebsd.org mailing list >> https://lists.freebsd.org/mailman/listinfo/freebsd-stable >> To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org" > > -- > This message has been scanned for viruses and > dangerous content by MailScanner, and is > believed to be clean. > freebsd-stable@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org" ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: FreeBSD 13.0 terrible performance in KVM
I'm running 12.2 and 13.0 on KVM using virtio and zfs. I am not having disk I/O issues. Jeff Love On 4/24/21 5:25 AM, dashdruid via freebsd-stable wrote: Hello List, I hope some other folks out there running FreeBSD on KVM as well. I set up a base VM while doing so I noticed that the disk operations are very slow. Many times I edit a file in vim or try to run a command there is a huge lag. I use UFS as the root filesystem. To have something to compare it with I have tested it against an OpenBSD 6.6 VM on the same host, same hardware. both have 1 vCPU and 1GB of ram, 20GB virtual disk (they are exactly on the same physical disk no raid or anything to have a fair comparison). Here is an example simple file search time for a non-existent file: FreeBSD 13 time find / -name cacert.pem real 0m30.656s user 0m0.516s sys 0m3.938s Second run even worse real 2m38.618s user 0m0.711s sys 0m6.882s While on the OpenBSD VM I get time find / -name cacert.pem real 0m2.258s user 0m0.290s sys 0m1.970s The amount of data is about the same on both systems but I would not consider this a "slight" performance degradation. If the base system is so slow then imagine putting Apache and other servers on top of it. Did anyone run into this? Unless there is a definitive solution I will opt out to using other BSD variants. ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org" -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: FreeBSD 13.0 terrible performance in KVM
> I hope some other folks out there running FreeBSD on KVM as well. I set up a base VM while doing so I noticed that the disk operations are very slow. Many times I edit a file in vim or try to run a command there is a huge lag. I noticed this on Ramnode--my VPS--and tech support there has told me it is due to their container set up with Docker(?). They made some adjustments and then it worked fine. ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: FreeBSD 13.0 terrible performance in KVM
We have over 50 FreeBSD VM on KVM for years, several Proxmox (5x,6x) and Centos (6.x,7.x) servers, and never experienced performance problem like this. Your example on fresh new 13 VM: # time -p find / -name cacert.pem real 0.28 user 0.00 sys 0.13 12.2 our syslog server: # time -p find / -name cacert.pem real 4.12 user 0.21 sys 3.77 Our hardware are Supermicro, IBM and Fujitsu servers with Xeon CPU-s, some with HW raid, others with ZFS as datastore, previous we had several IBM x3650 ... Everything was ok. No big difference between Linux and FreeBSD guests. We use Linux as guests only if we have to. ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
Re: FreeBSD 13.0 terrible performance in KVM
> Am 24.04.2021 um 11:25 schrieb dashdruid via freebsd-stable > : > > Hello List, > > I hope some other folks out there running FreeBSD on KVM as well. I set up a > base VM while doing so I noticed that the disk operations are very slow. Many > times I edit a file in vim or try to run a command there is a huge lag. It’s a huge and common problem that has been going on for years. I also had the same problem with XenServer. You can search bugzilla for „KVM“ bugs, as well as the forums. Apparently, it was mostly fixed for VMWare, but fixing for KVM is apparently very difficult. Even more so as there are many different versions of KVM around that all behave differently, depending on how you configure the virtual hardware (of which there are endless variations and permutations on how you attach with virtual devices to which virtual PCI-bus etc.pp.). It’s also likely fixed on AWS (but I do not use that, so I hardly care). E.g. when I created a KVM VM on my local workstation at work, it performed identically (more or less) to e.g. a CentOS VM. However, if I create a VM on our on-premise Openstack cloud, it achieves maybe 10% or 20% of the disk-IO-speed of a CentOS VM with the same volume type. There’s some work going on in some differentials, but I haven’t had the time to try. The problem is IMHO that most of the paid developers (for FreeBSD) these days either use it on bare metal (hello Netflix, EMC, Netapp, Netgate et.al.) or use it inside VMWare, where the main pain-points seem to have been fixed. Or they even use FreeBSD’s own hypervisor (bhyve). It’s a tragedy IMO and it totally rules out FreeBSD here around for almost all future use-cases (that are almost certainly moving to Openstack in the future). ___ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
