Oops - not paying close enough attention here - my bad Here is the actual performance of the NFS mounted drive: [root@o01 ~]# dd if=/dev/sdc of=/dev/null bs=4k status=progress 57427484672 bytes (57 GB, 53 GiB) copied, 200 s, 287 MB/s It's still running but this is more indicative of how thing are running... Ron Gage On 8/2/2025 12:45 PM, Ron Gage wrote:
Re: [ceph-users] Performance issues
All:
On 8/2/2025 12:20 PM, Anthony D'Atri wrote:
I suspect that the NVMe drives are client-class located on external systems, each with a conventional filesystem with big files that are exported to VMs that mount them as block devices. A lot of layers and media that aren’t up to a sustained workload.
The NVME is a Samsung 990 Plus. Not exactly entrprise grade, but it should do fairly well. It is also fairly new having picked it up yesterday. It's not going to be 100 MBit - for sure.
The NVME connection path: NVME -> USB C Interface -> Nas Server (ubuntu 24.04) -> 2.5 GBit Ethernet (NFS) -> ProxMox vmbr1
Raw device performance from my "nas" system: root@nas:~# hdparm -t /dev/sdb
/dev/sdb: Timing buffered disk reads: 1310 MB in 3.00 seconds = 436.21 MB/sec root@nas:~#
On Aug 2, 2025, at 12:13 PM,darren@soothill.com wrote:
As you rightly point out the 110MB/s it sounds very much like the traffic is going through the wrong interface or being limited. Limited - I agree. Wrong interface is unlikely - main network (192.168.0.0/23) has no route to the ceph network and vice versa - no gateway defined on the ceph network. So am I correct in my reading of this that this a virtual Ceph environment running on Proxmox?
What do you mean by this statement? " All Ceph drives are exposed and an NFS mounted NVME drive. “
Do I take this to mean that you 4 servers are all mounting the same NVME device over NFS? Just a bit confused as to the exact hardware setup here.
What is the performance you can get from a single Ceph OSD? Just do a simple dd to read not write to an OSD drive.
[root@o01 ~]# dd if=/dev/sdb of=10M bs=4k status=progress 5117947904 bytes (5.1 GB, 4.8 GiB) copied, 23 s, 223 MB/s 1310720+0 records in 1310720+0 records out 5368709120 bytes (5.4 GB, 5.0 GiB) copied, 23.9114 s, 225 MB/s [root@o01 ~]#
Also, `ceph tell osd.X bench`
[root@c01 ~]# ceph tell osd.2 bench { "bytes_written": 1073741824, "blocksize": 4194304, "elapsed_sec": 3.7980597760000001, "bytes_per_sec": 282707984.42536151, "iops": 67.402835947361353 } [root@c01 ~]#
Ron Gage
Darren
On 2 Aug 2025, at 15:25, Ron Gage<ron@rongage.org> wrote:
Hello from Detroit MI:
I have been doing some limited benchmarking of a Squid cluster. The arrangement of the cluster: Server Function c01 MGR, MON c02 MGR, MON o01 OSD o02 OSD o03 OSD o04 OSD
Each OSD has 2 x NVME disks for Ceph, each at 370 Gig
The backing network is as follows: ens18 Gigabit, mon-ip (192.168.0.0/23) regular MTU (1500) ens19 2.5 Gigabit, Cluster Network (10.0.0.0/24) Jumbo MTU (9000)
Behind all this is a small ProxMox cluster. All Ceph machines are running on a single node. All Ceph drives are exposed and an NFS mounted NVME drive. All Ceph OSD drives are mounted with no cache and single controller per drive. Networking bridges are all set to either MTU 9000 or MTU 1500 as appropriate.
iPerf3 is showing 2.46 Gbit/sec between servers c01 and o01 on the ens19 network. Firewall is off all the way around. OS is CentOS 10. SELinux of disabled. No network enhancements have been performed (increasing send/rcv buffer size, queue length, etc).
The concern given all this: rados bench can't exceed 110 MB/s in all tests. In fact if I didn't know better I would swear that the traffic is being either throttled or is somehow routing through a 1Gbit network. The numbers that are returning from rados bench are acting like saturation at Gigabit and not exhibiting any evidence of being on a 2.5 Gbit network. Monitoring at both Ceph and ProxMox consoles confirm the same. Cluster traffic is confirmed to be going out ens19 - tested via tcpdump.
Typical command line used for rados bench: rados bench -p s3block 20 write
What the heck am I doing wrong here?
Ron Gage
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