[LUDOC-331] record new default for inode size on MDT is 2K

• Status: Resolved
• Project: Lustre Documentation
• Type: Bug
• Priority: Minor
• Reporter: Richard Henwood (Inactive)
• Assignee: Lustre Manual Triage
• Resolution: Fixed
• Severity: 3

Description

This section needs to be reviewed to ensure accuracy:

https://build.hpdd.intel.com/job/lustre-manual/lastSuccessfulBuild/artifact/lustre_manual.xhtml#dbdoclet.50438256_31079

The new MDT default inode size is 2K. I am trying to discover when the default change was made.

Comments

[Andreas Dilger]

This change was made in commit 2.0.60.0-8-geb012d4, so 2048 bytes per inode has been the default since Lustre 2.1.0.

To be clear, there are two separate parameters related to inode size for ldiskfs:

• inode_size (-I): controls how large the inode structure is, which affects how much extra space there is for extended attributes (layout, etc) in the inode. The default inode size is 512 bytes, which is typically enough for a 4-stripe file. Must be a power-of-two value.
• bytes_per_inode (-i): controls how many inodes are created in the filesystem as a ratio of (filesystem size / inode count). The default is 2048 bytes per inode (actually inode_size + 1536), or in other words one inode for every 2KB of the block device. Must be a power-of-two value.

[Keith Mannthey (Inactive)]

e2fsprogs-1.42.13.wc4-7.el7.x86_64

When building an MDT with 100% default options my inodes size came out to be 512. Please double check this info before updating the manual.

[Gerrit Updater]

Andreas Dilger ([e-mail]) uploaded a new patch: http://review.whamcloud.com/19786
Subject: LUDOC-331 setup: explain ldiskfs inode size/ratio better
Project: doc/manual
Branch: master
Current Patch Set: 1
Commit: be913d9c1b4c411ab2a56c3c9a4634467cb43c9e

[Gerrit Updater]

Andreas Dilger ([e-mail]) merged in patch http://review.whamcloud.com/19786/
Subject: LUDOC-331 setup: explain ldiskfs inode size/ratio better
Project: doc/manual
Branch: master
Current Patch Set:
Commit: 183c459f8a4370b70d039fb30711de20cadbdce1

[Gerrit Updater]

Andreas Dilger ([e-mail]) uploaded a new patch: http://review.whamcloud.com/21262
Subject: LUDOC-331 setup: improve ldiskfs formatting options
Project: doc/manual
Branch: master
Current Patch Set: 1
Commit: 2f3e643b8129e0f0210cd95fc0f38b52c596d2d8

[Gerrit Updater]

Andreas Dilger ([e-mail]) merged in patch http://review.whamcloud.com/21262/
Subject: LUDOC-331 setup: improve ldiskfs formatting options
Project: doc/manual
Branch: master
Current Patch Set:
Commit: 8c05589f167ff34ab9806f29ecfb92d424f65739