Which OS/kernel you are running with ?
Try setting bigger read_ahead_kb for sequential runs.
Thanks & Regards
Somnath
From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx]
On Behalf Of EP Komarla
Sent: Tuesday, July 26, 2016 4:38 PM
To: ceph-users@xxxxxxxxxxxxxx
Subject: Ceph performance pattern
Hi,
I am showing below fio results for Sequential Read on my Ceph cluster. I am trying to understand this pattern:
- why there is a dip in the performance for block sizes 32k-256k?
- is this an expected performance graph?
- have you seen this kind of pattern before
My cluster details:
Ceph: Hammer release
Cluster: 6 nodes (dual Intel sockets) each with 20 OSDs and 4 SSDs (5 OSD journals on one SSD)
Client network: 10Gbps
Cluster network: 10Gbps
FIO test:
- 2 Client servers
- Sequential Read
- Run time of 600 seconds
- Filesize = 1TB
- 10 rbd images per client
- Queue depth=16
Any ideas on tuning this cluster? Where should I look first?
Thanks,
- epk
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