[LU-16938] "lfs setstripe -C -1" stripes too widely, should be limited to OST_COUNT

• Type: Improvement
• Resolution: Fixed
• Priority: Major
• Fix Version/s: Lustre 2.16.0
• Affects Version/s: Lustre 2.15.0
• Severity: 3
• Assignee: Rajeev Mishra
• Reporter: Rajeev Mishra

Description

I am reaching out to seek clarification regarding the expected behavior of the "lfs setstripe" command when using the -C -1 option.

Currently, it appears that this command is creating a higher stripe count than anticipated. For instance, on my test system, it generated a stripe count of 2727 for a single file. This count exceeds the allowed limit of LOV_MAX_STRIPE_COUNT. 

I am uncertain about the appropriate solution to address this issue related to the "-1" argument. I have contemplated the following options:

1.    Consider making the option -1 illegal, preventing its usage altogether.

2.    Implement a mechanism to automatically set the stripe count to the maximum allowed value (LOV_MAX_STRIPE_COUNT) if the count exceeds this limit.

I would greatly appreciate your input and guidance in this matter. It is worth noting that setting the stripe count higher than LOV_MAX_STRIPE_COUNT leads to other problems, such as the failure of the "llapi_layout_get_by_fd" API to open the file.

Please let me know your input.

Issue Links

• is related to: LU-17925 sanity-flr test_0b: lfs mirror create: cannot create composite file: Numerical result out of range
• is related to: LU-17199 'lfs setstripe -C -1' can be set beyond overstripe count > 2000
• is related to: LU-18244 add 'lfs mkdir -C -N' overstriping support
• is related to: LU-16623 lod_statfs_and_check() does not skip unusable OSTs
• is related to: LU-13748 'lfs setstripe -C -1' stripes too widely