Bug 2037716
| Summary: | [cee/sd][doc] Need correction in chapter "9.6 Tuning Ceph BlueStore for small writes" of RHCS 4 Administration Guide | ||
|---|---|---|---|
| Product: | [Red Hat Storage] Red Hat Ceph Storage | Reporter: | Prasanth M V <pmv> |
| Component: | Documentation | Assignee: | Kusuma <kbg> |
| Documentation sub component: | Administration Guide | QA Contact: | Pawan <pdhiran> |
| Status: | CLOSED CURRENTRELEASE | Docs Contact: | Ranjini M N <rmandyam> |
| Severity: | medium | ||
| Priority: | unspecified | CC: | hyelloji, kbg, rmandyam |
| Version: | 4.0 | Keywords: | Documentation, NoDocsQEReview |
| Target Milestone: | --- | ||
| Target Release: | Backlog | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | If docs needed, set a value | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2022-04-04 11:11:54 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Describe the issue: In the "Administration Guide, Chapter 9.6" Of RHCS4 document it is mentioned that In BlueStore, the raw partition is allocated and managed in chunks of bluestore_min_alloc_size. By default, bluestore_min_alloc_size is 64 KB for HDDs, and 16 KB for SSDs. But from RHCS 4.1 the default value of bluestore_min_alloc_size for solid state devices(SSDs) has been changed from 16KB to 4KB. The current value of bluestore_min_alloc_size_ssd is 4 KB. The same has been included in the release note of RHCS 4.1 but not in the "Administration Guide, Chapter 9.6" of RHCS4 document. In RHCS 4.1 and Newer: #ceph daemon osd.0 config show | grep bluestore_min_alloc_size_ "bluestore_min_alloc_size_hdd": "65536", "bluestore_min_alloc_size_ssd": "4096", Suggestions for improvement: Requesting to make the change in the RHCS4 document about the statement of bluestore_min_alloc_size for solid state devices(SSDs) to 4KB in the "Administration Guide, Chapter 9.6" as well. Currently in the document: In BlueStore, the raw partition is allocated and managed in chunks of bluestore_min_alloc_size. By default, bluestore_min_alloc_size is 64 KB for HDDs, and 16 KB for SSDs. Expected change in the document: In BlueStore, the raw partition is allocated and managed in chunks of bluestore_min_alloc_size. By default, bluestore_min_alloc_size is 64 KB for HDDs, and 4 KB for SSDs. Document URL: https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/4/html/administration_guide/osd-bluestore#tuning-ceph-bluestore-for-small-writes_admin Chapter/Section Number and Title: 9.6. Tuning Ceph BlueStore for small writes Product Version: Redhat Ceph Storage 4 Any other versions of this document that also needs this update: The changes are implemented on RHCS 4.1. But we have a common "Administration Guide" for all RHCS4.So the change expecting in the Administration Guide. Additional information: We have a KCS for the same issue described: https://access.redhat.com/solutions/3829321