Hi,
hmm i think 200 MByte/s is really bad. Is your Cluster in production
right now?
So if you start a storage migration you get only 200 MByte/s right?
I think it would be awesome if you get 1000 MByte/s
Where is the Bottleneck?
A FIO Test from Sebastien Han give us 400 MByte/s raw performance from
the P3700.
https://www.sebastien-han.fr/blog/2014/10/10/ceph-how-to-test-if-your-ssd-is-suitable-as-a-journal-device/
How could it be that the rbd client performance is 50% slower?
Regards
Am 21.07.16 um 12:15 schrieb Nick Fisk:
I've had a lot of pain with this, smaller block sizes are even worse. You want to try and minimize latency at every point as there
is no buffering happening in the iSCSI stack. This means:-
1. Fast journals (NVME or NVRAM)
2. 10GB or better networking
3. Fast CPU's (Ghz)
4. Fix CPU c-state's to C1
5. Fix CPU's Freq to max
Also I can't be sure, but I think there is a metadata update happening with VMFS, particularly if you are using thin VMDK's, this
can also be a major bottleneck. For my use case, I've switched over to NFS as it has given much more performance at scale and less
headache.
For the RADOS Run, here you go (400GB P3700):
Total time run: 60.026491
Total writes made: 3104
Write size: 4194304
Object size: 4194304
Bandwidth (MB/sec): 206.842
Stddev Bandwidth: 8.10412
Max bandwidth (MB/sec): 224
Min bandwidth (MB/sec): 180
Average IOPS: 51
Stddev IOPS: 2
Max IOPS: 56
Min IOPS: 45
Average Latency(s): 0.0193366
Stddev Latency(s): 0.00148039
Max latency(s): 0.0377946
Min latency(s): 0.015909
Nick
-----Original Message-----
From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of Horace
Sent: 21 July 2016 10:26
To: wr@xxxxxxxx
Cc: ceph-users@xxxxxxxxxxxxxx
Subject: Re: Ceph + VMware + Single Thread Performance
Hi,
Same here, I've read some blog saying that vmware will frequently verify the locking on VMFS over iSCSI, hence it will have much
slower performance than NFS (with different locking mechanism).
Regards,
Horace Ng
----- Original Message -----
From: wr@xxxxxxxx
To: ceph-users@xxxxxxxxxxxxxx
Sent: Thursday, July 21, 2016 5:11:21 PM
Subject: Ceph + VMware + Single Thread Performance
Hi everyone,
we see at our cluster relatively slow Single Thread Performance on the iscsi Nodes.
Our setup:
3 Racks:
18x Data Nodes, 3 Mon Nodes, 3 iscsi Gateway Nodes with tgt (rbd cache off).
2x Samsung SM863 Enterprise SSD for Journal (3 OSD per SSD) and 6x WD
Red 1TB per Data Node as OSD.
Replication = 3
chooseleaf = 3 type Rack in the crush map
We get only ca. 90 MByte/s on the iscsi Gateway Servers with:
rados bench -p rbd 60 write -b 4M -t 1
If we test with:
rados bench -p rbd 60 write -b 4M -t 32
we get ca. 600 - 700 MByte/s
We plan to replace the Samsung SSD with Intel DC P3700 PCIe NVM'e for
the Journal to get better Single Thread Performance.
Is anyone of you out there who has an Intel P3700 for Journal an can
give me back test results with:
rados bench -p rbd 60 write -b 4M -t 1
Thank you very much !!
Kind Regards !!
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@xxxxxxxxxxxxxx
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
