[LU-9501] Flag for mke2fs to automatically adjust number of inodes

• Status: Resolved
• Project: Lustre
• Type: Improvement
• Priority: Major
• Reporter: Artem Blagodarenko (Inactive)
• Assignee: WC Triage
• Resolution: Fixed
• Labels: e2fsprogs, patch

Description

In certain cases device size where filesystem is created is not know in advance, and it's impractical to try guess correct inode ratio to satisfy filesystem limitations (which is 4G inodes for ext4 and ldiskfs).
We need a flag to tell mke2fs to limit inode count to match current filesystem limits.
Example of current behavior:

# mke2fs  -i 1024 img
mke2fs 1.42.13.x2 (29-Sep-2016)
mke2fs: too many inodes (5269225472), raise inode ratio?
root@kvkvm1oem(0):~#

Proposed behavior (example only, feel free to change message text):

# mke2fs  -i 1024 --adjust-inode-count img
mke2fs 1.42.13.x2 (29-Sep-2016)
mke2fs: too many inodes (5269225472), changing to <supported FS limit> 
... formatting continues ...

Comments

[Andreas Dilger]

I think if you don't specify "-I" then it will cap the inode count at 4B?

In any case, I think that this should really be a fix in mke2fs and should probably be discussed on the linux-ext4 mailing list?

[Artem Blagodarenko (Inactive)]

Hello Andreas.

Thank you for quick answer. I am agree that mke2fs requires such useful modification. But this feature is very important now for customers running Lustre FS. Currently users which what to create custom large enough cluster, hit this error message and need to readjust config scripts manually, that stops deployment with other automatic parts. This little fix solves the problem and make customers happy. Can we apply it now and switch to another one from ext4 latter?

Anyway I will upload this patch here. It can be useful if we decide land it or sent patch to linux-ext4.

Thanks.

[Andreas Dilger]

IMHO, I don't think we even need an option for this? Just limit the inode count to 4B inodes automatically rather than returning an error.

[Gerrit Updater]

Artem Blagodarenko ([e-mail]) uploaded a new patch: https://review.whamcloud.com/27111
Subject: LU-9501 mke2fs: avoid inode number error with large FS
Project: tools/e2fsprogs
Branch: master-lustre
Current Patch Set: 1
Commit: d8b68ec2ccf56dd97cb7be30188d9f745206e534

[Artem Blagodarenko (Inactive)]

>Just limit the inode count to 4B inodes automatically rather than returning an error.
This patch exact this idea

[Gerrit Updater]

Andreas Dilger ([e-mail]) merged in patch https://review.whamcloud.com/27111/
Subject: LU-9501 mke2fs: avoid inode number error with large FS
Project: tools/e2fsprogs
Branch: master-lustre
Current Patch Set:
Commit: ec44b0534beb51ce70bb9b997cbbad2476506b2a