Red Hat Bugzilla – Bug 1300666
Performance profile for RHEL for SAP HANA
Last modified: 2016-01-26 10:49:58 EST
Created attachment 1116919 [details]
First draft of a performance profile for SAP HANA. Rewritten for RHEL7 based of the one for RHEL6.
Description of problem:
RHEL7.2 for SAP HANA is expected to be certified within the next weeks. But there is still a performance profile missing to maximize the performance when SAP HANA is run on RHEL7.2 as it is already for RHEL6.
Steps to Reproduce:
1. Try to tune your system with # tuned-adm profile sap-hana
2. The attempt will fail due to missing profile
Profile sap-hana missing and not yet available
Availability inside a future RHEL7.2 for SAP HANA channel
See attachment /etc/tuned/sap-hana/tuned.conf
Hi Jurgen, thanks for sending this! Some comments inline --
# tuned configuration for SAP HANA
# Written by: firstname.lastname@example.org
Hmm, we still have this in tuned, but the rest of the profiles moved away from readahead_multiply in RHEL7. It got quite complicated to ensure that readahead values were as expected during profile rollback/forward and disk hotplug. So we went with a static-ish value. The throughput-performance profile which this profile includes, sets
Which means that it will ensure that readahead is always 4096 or larger. If the user sets it manually to anything larger than 4096, tuned will leave it alone. So, I would request that you also move to this method, and if 4096 works for SAP, then perhaps drop the [disk] section entirely?
# If a workload mostly uses anonymous memory and it hits this limit, the entire
# working set is buffered for I/O, and any more write buffering would require
# swapping, so it's time to throttle writes until I/O can catch up. Workloads
# that mostly use file mappings may be able to use even higher values.
# The generator of dirty data starts writeback at this percentage (system default
# is 20%)
I see you copied this blurb from throughput-performance. I'd probably just drop the comment entirely. Upstream default is 20, but RHEL default is 40. And this profile sets vm.dirty_ratio=10.
vm.dirty_ratio = 10
This is redundant as you've set force_latency=1. You can drop the bootloader thing and still get the same performance/behavior.
There are already some SAP profiles in RHEL-7 (all bits from RHEL-6 should be there) , . Is this profile different from them? How should be this profile named and in which sub-package should it be delivered?
Here's the old bugzilla requesting the tuned-sap-hana package for RHEL7 which was resolved for RHEL7.2: https://bugzilla.redhat.com/show_bug.cgi?id=1246642
(In reply to Frank Danapfel from comment #4)
> Here's the old bugzilla requesting the tuned-sap-hana package for RHEL7
> which was resolved for RHEL7.2:
Is this request for addition of new profile? Or edit of the existing SAP profiles? Or should be this bug closed as already resolved?