Bug 1403772

Summary:	Performance recommendations for RAID 5 setup
Product:	[Red Hat Storage] Red Hat Gluster Storage	Reporter:	Sachidananda Urs <surs>
Component:	Documentation	Assignee:	Anjana Suparna Sriram <asriram>
Status:	CLOSED CURRENTRELEASE	QA Contact:	SATHEESARAN <sasundar>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	rhgs-3.2	CC:	apaladug, guillaume.pavese, rhs-bugs, sasundar, storage-doc, storage-qa-internal
Target Milestone:	---
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Hardware:	All
OS:	Linux
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Fixed In Version:		Doc Type:	If docs needed, set a value
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Last Closed:	2020-12-09 12:35:34 UTC	Type:	Bug
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Embargoed:
Bug Depends On:
Bug Blocks:	1277939, 1411907, 1436695

Description Sachidananda Urs 2016-12-12 11:00:48 UTC

Description of problem:

Some of the customers use RAID 5 in their hyperconverged setup.
Currently we do not have any performance recommendations on how to setup
the logical volumes on RAID 5 disks.

Raising this bug as a place holder for follow up with perf team.

Comment 4 SATHEESARAN 2017-01-10 17:45:24 UTC

Manoj,

If RAID 5 device is used for RHGS brick backend, what should be the data disk count ?

The intention of asking this question is pvcreate would require --dataalignment value, what would be the value there ?

Comment 5 Manoj Pillai 2017-01-11 09:43:51 UTC

For N+1 RAID-5, where N is the number of data disks, here's what I'd suggest:

* N=4, would be a good choice
* RAID-5 stripe-unit size of 64KB
* enable write-back caching in the RAID controller (if it has BBU).
* [stripe_unit_size=64KB, data_stripe_size = 64*4 = 256KB]
* pvcreate --dataalignment $data_stripe_size <device>
* vgcreate --physicalextentsize $data_stripe_size <vg_name> <device>
* thin pool chunk size of $data_stripe_size
* mkfs.xfs: use -d su=<>,sw=<> option, with stripe_unit_size and N, resp.

I'm assuming this will go through some testing before it goes out to customers? :).

Comment 6 Manoj Pillai 2017-01-11 10:17:42 UTC

(In reply to Manoj Pillai from comment #5)
> For N+1 RAID-5, where N is the number of data disks, here's what I'd suggest:
> 
> * N=4, would be a good choice
> * RAID-5 stripe-unit size of 64KB
> * enable write-back caching in the RAID controller (if it has BBU).
> * [stripe_unit_size=64KB, data_stripe_size = 64*4 = 256KB]

That should have been: data_stripe_size = 64*N.

Comment 9 Amar Tumballi 2018-04-02 13:26:06 UTC

There is no action in last 11 months, should we close this?

Comment 11 SATHEESARAN 2020-12-09 12:35:34 UTC

RHHI-V supports usage of RAID 5 and there are no specific performance penalities reported

Comment 12 Red Hat Bugzilla 2023-09-14 03:36:00 UTC

The needinfo request[s] on this closed bug have been removed as they have been unresolved for 1000 days