Hi All - I use qemu on my centOS 7.7 box that has software raid of 2- SSD disks. I installed an nVME drive in the computer also. I tried to insall CentOS8 on it (the physical /dev/nvme0n1 with the -hda /dev/nvme0n1 as the disk. The process started installing but is really "slow" - I was expecting with the nvme device it would be much quicker. Is there something I am missing how to get a faster disk access ? Thanks, Jerry
On 10/12/19 11:38 PM, Jerry Geis wrote:> Hi All - I use qemu on my centOS 7.7 box that has software raid of 2- SSD > disks. > > I installed an nVME drive in the computer also. I tried to insall CentOS8 > on it > (the physical /dev/nvme0n1 with the -hda /dev/nvme0n1 as the disk. > > The process started installing but is really "slow" - I was expecting with > the nvme device it would be much quicker. > > Is there something I am missing how to get a faster disk access ?You should try with some other OS to make sure it is not a hardware (BIOS/MB) problem. Maybe try with Windows or some other Linux and compare speeds? Also check if there is a firmware/BIOS update for the nVME controler...> > Thanks, > > Jerry > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >-- Ljubomir Ljubojevic (Love is in the Air) PL Computers Serbia, Europe StarOS, Mikrotik and CentOS/RHEL/Linux consultant
I have CentOS 8 install solely on one nvme drive and it works fine and relatively quickly. /dev/nvme0n1p4????????? 218G?? 50G? 168G? 23% / /dev/nvme0n1p2????????? 2.0G? 235M? 1.6G? 13% /boot /dev/nvme0n1p1????????? 200M? 6.8M? 194M?? 4% /boot/efi You might want to partition the device (p3 is swap) Alan On 13/10/2019 10:38, Jerry Geis wrote:> Hi All - I use qemu on my centOS 7.7 box that has software raid of 2- SSD > disks. > > I installed an nVME drive in the computer also. I tried to insall CentOS8 > on it > (the physical /dev/nvme0n1 with the -hda /dev/nvme0n1 as the disk. > > The process started installing but is really "slow" - I was expecting with > the nvme device it would be much quicker. > > Is there something I am missing how to get a faster disk access ? > > Thanks, > > Jerry > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos
Hi Alan,
Yes I have partitioned similar - with a swap. but as I mentioned slow!
What command line do you use ?
Device Boot Start End Blocks Id System
/dev/nvme0n1p1 2048 102402047 51200000 83 Linux
/dev/nvme0n1p2 102402048 110594047 4096000 82 Linux swap /
Solaris
/dev/nvme0n1p3 110594048 112642047 1024000 6 FAT16
/dev/nvme0n1p4 112642048 3907028991 1897193472 83 Linux
Thanks,
Jerry
> How do you measure the slowness? Use fio or bonnie++ to share some number.By it taking more than 6 hours to "install" CentOS 8 in the guest :) Jerry
On 13/10/19 00:57, Jerry Geis wrote:>> How do you measure the slowness? Use fio or bonnie++ to share some number. > > By it taking more than 6 hours to "install" CentOS 8 in the guest :) > > Jerry > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >Hi Jerry, 6 hours are too much. First of all you need to check your nvme performace (dd can help? dd if=/dev/zero of=/test bs=1M count=10000 andd see results. If you want results more benchmark oriented you could try bonnie++ as suggested by Jerry). Other this, have you got kvm module loaded and enabled cpu virtualization option in the BIOS? If yes, have you got created the VM using --accelerate? Have you tried another distro on VM? Actually I can't install C8 on my nmve drive. It powers this workstation and is still 7.7, at the moment I don't install C8 because it is unusable. Hope that helps.
>6 hours are too much. First of all you need to check your nvme >performace (dd can help? dd if=/dev/zero of=/test bs=1M count=10000 andd >see results. If you want results more benchmark oriented you could try >bonnie++ as suggested by Jerry).>Other this, have you got kvm module loaded and enabled cpu >virtualization option in the BIOS?>If yes, have you got created the VM using --accelerate?>Have you tried another distro on VM?I mounted the partition under C7.7 and ran the nvme test. Pretty much came back in seconds for 10G test. dd if=/dev/zero of=test bs=1M count=10000 10000+0 records in 10000+0 records out 10485760000 bytes (10 GB) copied, 5.45451 s, 1.9 GB/s Yes kvm_intel is loaded as a module. I am using the "-hda /dev/nvme0n1" when I run qemu.... I'm thinking this works find for my other "img" files - but does not work for "well" for my physical NVME. What is the correct argument perhaps to use for running a physical NVME disk as a qemu guest ?? Thanks, Jerry
On Sat, 12 Oct 2019 at 17:38, Jerry Geis <jerry.geis at gmail.com> wrote:> > Hi All - I use qemu on my centOS 7.7 box that has software raid of 2- SSD > disks. > > I installed an nVME drive in the computer also. I tried to insall CentOS8 > on it > (the physical /dev/nvme0n1 with the -hda /dev/nvme0n1 as the disk. > > The process started installing but is really "slow" - I was expecting with > the nvme device it would be much quicker. > > Is there something I am missing how to get a faster disk access ? >Does anything get listed in the guest or the virtual-machine-host system for errors? The reasons I could see for very very slow nvme would be that something is trying to write too small a sector for the drive and flushing the drive. Depending on the nvme it might be set up to read mostly and write rarely, read/write even or write a lot/read in blocks. VM's usually are mixed use and get really weird behavior on the others. If the nvme is expecting large writes and it is getting small ones which don't "fit" it will 1) wear out the nvme because it is basically rewriting a full block every time even if it is only changing 5 k and 2) is slow because all those little writes are blocking. I would look to see if the device is mostly in Device Wait and if io errors are showing up. -- Stephen J Smoogen.