[LU-13841] error messages need additional explanation for lctl pcc commands

• Type: Bug
• Resolution: Fixed
• Priority: Trivial
• Affects Version/s: Lustre 2.14.0
• Environment: Virtual machine
• Severity: 3
• Assignee: WC Triage
• Reporter: Vikentsi Lapa

Description

 

From user  perspective:

• different cases reports same error. 
• error message itself does not explain what File exists, so it should be documented or changed. Also error message assumed that user knows PCC internals to understand it.

 

From my point of view this can fixed by added some notes or explanation to documentation, or change error message itself, like "cache already enabled for ..."

 

Steps to reproduce:

Directory  for cache is created and exists.

1. ls /mnt/pcc2

#  lctl pcc add /mnt/lustre /mnt/pcc2 --param "projid={100} rwid=2"

Try to add pcc cache multiple times with same rwid

#  lctl pcc add /mnt/lustre /mnt/pcc2 --param "projid={100} rwid=2"

lctl pcc pcc: error: setting llite.lustre-ffff8b405721f800.pcc='add /mnt/pcc2 projid={100} rwid=2': File exists (17)

 

Try to add pcc cache with same path to /mtn/pcc2 but with  with different rwid

[#  lctl pcc add /mnt/lustre /mnt/pcc2 --param "projid={100} rwid=5"

lctl pcc pcc: error: setting llite.lustre-ffff8b405721f800.pcc='add /mnt/pcc2 projid={100} rwid=5*': File exists (17)*

 

Use incorrect arguments: to get path with numbers

1. lctl pcc add /mnt/lustre pccro --param projid={100} rwid=2
   add: must specify mount path and PCC path 3:6
   Add a PCC backend to a client.
   usage: lctl pcc add <mntpath> <pccpath> [--param|-p <param>]
   mntpath: Lustre mount point.
   pccpath: Path of the PCC backend.
   param: Setting parameters for PCC backend.

 What is "PCC path 3:6" about? Similar to lctl pcc del

lctl pcc del /mnt/pcc2
del: must speficy mount path and PCC path 1:2
Delete the specified PCC backend on a client.
usage: clt pcc del <mntpath> <pccpath>

 

Typo in error mesage:

del: must speficy mount path and PCC path 1:2  -> specify

 

Incorrect number of arguments in help output:

1. lctl pcc list
   list: require 2 arguments
   List all PCC backends on a client.
   usage: lctl pcc list <mntpath>**Command output shows 2 arguments in help but only one is required.

 

Issue Links

• is related to: LU-10499 Readonly Persistent Client Cache support