Can you point me to the directions for the kernel mode iscsi backend. I was following these directions https://docs.ceph.com/docs/master/rbd/iscsi-target-cli/
Thanks, Ryan On Fri, Oct 25, 2019 at 11:29 AM Mike Christie <mchri...@redhat.com> wrote: > On 10/25/2019 09:31 AM, Ryan wrote: > > I'm not seeing the emulate_3pc setting under disks/rbd/diskname when > > emulate_3pc is only for kernel based backends. tcmu-runner always has > xcopy on. > > > calling info. A google search shows that SUSE Enterprise Storage has it > > available. I thought I had the latest packages, but maybe not. I'm using > > tcmu-runner 1.5.2 and ceph-iscsi 3.3. Almost all of my VMs are currently > > on Nimble iSCSI storage. I've actually tested from both and performance > > is the same. Doing the math off the ceph status does show it using 64K > > blocks in both cases. > > > > Control Values > > - hw_max_sectors .. 1024 > > - max_data_area_mb .. 256 (override) > > - osd_op_timeout .. 30 > > - qfull_timeout .. 5 > > > > On Fri, Oct 25, 2019 at 4:46 AM Maged Mokhtar <mmokh...@petasan.org > > <mailto:mmokh...@petasan.org>> wrote: > > > > Actually this may not work if moving from a local datastore to Ceph. > > For iSCSI xcopy, both the source and destination need to be > > accessible by the target such as in moving vms across Ceph > > datastores. So in your case, vmotion will be handled by VMWare data > > mover which uses 64K block sizes. > > > > On 25/10/2019 10:28, Maged Mokhtar wrote: > >> > >> For vmotion speed, check "emulate_3pc" attribute on the LIO > >> target. If 0 (default), VMWare will issue io in 64KB blocks which > >> gives low speed. if set to 1 this will trigger VMWare to use vaai > >> extended copy, which activates LIO's xcopy functionality which > >> uses 512KB block sizes by default. We also bumped the xcopy block > >> size to 4M (rbd object size) which gives around 400 MB/s vmotion > >> speed, the same speed can also be achieved via Veeam backups. > >> > >> /Maged > >> > >> On 25/10/2019 06:47, Ryan wrote: > >>> I'm using CentOS 7.7.1908 with kernel 3.10.0-1062.1.2.el7.x86_64. > >>> The workload was a VMware Storage Motion from a local SSD backed > >>> datastore to the ceph backed datastore. Performance was measured > >>> using dstat on the iscsi gateway for network traffic and ceph > >>> status as this cluster is basically idle. I changed > >>> max_data_area_mb to 256 and cmdsn_depth to 128. This appears to > >>> have given a slight improvement of maybe 10MB/s. > >>> > >>> Moving VM to the ceph backed datastore > >>> io: > >>> client: 124 KiB/s rd, 76 MiB/s wr, 95 op/s rd, 1.26k op/s wr > >>> > >>> Moving VM off the ceph backed datastore > >>> io: > >>> client: 344 MiB/s rd, 625 KiB/s wr, 5.54k op/s rd, 62 op/s wr > >>> > >>> I'm going to test bonnie++ with an rbd volume mounted directly on > >>> the iscsi gateway. Also will test bonnie++ inside a VM on a ceph > >>> backed datastore. > >>> > >>> On Thu, Oct 24, 2019 at 7:15 PM Mike Christie > >>> <mchri...@redhat.com <mailto:mchri...@redhat.com>> wrote: > >>> > >>> On 10/24/2019 12:22 PM, Ryan wrote: > >>> > I'm in the process of testing the iscsi target feature of > >>> ceph. The > >>> > cluster is running ceph 14.2.4 and ceph-iscsi 3.3. It > >>> consists of 5 > >>> > >>> What kernel are you using? > >>> > >>> > hosts with 12 SSD OSDs per host. Some basic testing moving > >>> VMs to a ceph > >>> > backed datastore is only showing 60MB/s transfers. However > >>> moving these > >>> > back off the datastore is fast at 200-300MB/s. > >>> > >>> What is the workload and what are you using to measure the > >>> throughput? > >>> > >>> If you are using fio, what arguments are you using? And, > >>> could you > >>> change the ioengine to rbd and re-run the test from the > >>> target system so > >>> we can check if rbd is slow or iscsi? > >>> > >>> For small IOs, 60 is about right. > >>> > >>> For 128-512K IOs you should be able to get around 300 MB/s > >>> for writes > >>> and 600 for reads. > >>> > >>> 1. Increase max_data_area_mb. This is a kernel buffer > >>> lio/tcmu uses to > >>> pass data between the kernel and tcmu-runner. The default is > >>> only 8MB. > >>> > >>> In gwcli cd to your disk and do: > >>> > >>> # reconfigure max_data_area_mb %N > >>> > >>> where N is between 8 and 2048 MBs. > >>> > >>> 2. The Linux kernel target only allows 64 commands per iscsi > >>> session by > >>> default. We increase that to 128, but you can increase this > >>> to 512. > >>> > >>> In gwcli cd to the target dir and do > >>> > >>> reconfigure cmdsn_depth 512 > >>> > >>> 3. I think ceph-iscsi and lio work better with higher queue > >>> depths so if > >>> you are using fio you want higher numjobs and/or iodepths. > >>> > >>> > > >>> > What should I be looking at to track down the write > >>> performance issue? > >>> > In comparison with the Nimble Storage arrays I can see > >>> 200-300MB/s in > >>> > both directions. > >>> > > >>> > Thanks, > >>> > Ryan > >>> > > >>> > > >>> > _______________________________________________ > >>> > ceph-users mailing list -- ceph-users@ceph.io > >>> <mailto:ceph-users@ceph.io> > >>> > To unsubscribe send an email to ceph-users-le...@ceph.io > >>> <mailto:ceph-users-le...@ceph.io> > >>> > > >>> > >>> > >>> _______________________________________________ > >>> ceph-users mailing list -- ceph-users@ceph.io <mailto: > ceph-users@ceph.io> > >>> To unsubscribe send an email to ceph-users-le...@ceph.io <mailto: > ceph-users-le...@ceph.io> > >> > >> _______________________________________________ > >> ceph-users mailing list -- ceph-users@ceph.io <mailto: > ceph-users@ceph.io> > >> To unsubscribe send an email to ceph-users-le...@ceph.io <mailto: > ceph-users-le...@ceph.io> > > > >
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