[lustre-discuss] Lustre Manual Bug Report: 25.2.2. Enabling and Tuning Root Squash

[Dilger, Andreas]

One thing that is important to note here is that the syntax of "conf_param" is not the same as "set_param" and "get_param".  The conf_param syntax is what sets the parameters permanently in the configuration log, while {get,set}_param run on the local node only.

There is a newer "lctl set_param -P" interface that was added, to allow permanently setting parameters using the (IMHO more familiar) "set_param" syntax, but it has some problems that currently prevent it from being used more widely.  There is a Jira ticket open for this that has been getting some attention recently, and hopefully the "set_param -P" functionality will be able to replace conf_param completely in the future.

Cheers, Andreas

On Jun 6, 2017, at 05:41, Gibbins, Faye <Faye.Gibbins at cirrus.com> wrote:
> 
> Hi,
>  
> I think I’ve found a bug in the manual: https://build.hpdd.intel.com/job/lustre-manual/lastSuccessfulBuild/artifact/lustre_manual.xhtml#dbdoclet.50438221_48757 I’ve included it below in case this is the correct place to report it. If not please let me know and I’ll submit it elsewhere.
>  
> In section 25.2.2. Enabling and Tuning Root Squash, the bit that says:
>  
> Snip---
> Root squash parameters can also be changed with the lctl conf_param command. For example:
>  
> mgs# lctl conf_param testfs.mdt.root_squash="1000:101"
> mgs# lctl conf_param testfs.mdt.nosquash_nids="*@tcp"
> Snip---
>  
> Should be IMHO:
>  
> Snip---
> Root squash parameters can also be changed with the lctl conf_param command. For example:
>  
> mgs# lctl conf_param mdt.testfs-MDT0000.root_squash="1000:101"
> mgs# lctl conf_param mdt.testfs-MDT0000.nosquash_nids="*@tcp"
> Snip---
>  
> Here is an example of me using my version compared to the documentation version using Lustre 2.8 on RHEL 7:
>  
> Snip---
> 0 edi-vf-1-5:audiodb-MDT0000# lctl get_param mdt.audiodb-MDT0000.root_squash
> mdt.audiodb-MDT0000.root_squash=0:0
> 0 edi-vf-1-5:audiodb-MDT0000# lctl set_param mdt.audiodb-MDT0000.root_squash="0:1"
> mdt.audiodb-MDT0000.root_squash=0:1
> 0 edi-vf-1-5:audiodb-MDT0000# lctl get_param mdt.audiodb-MDT0000.root_squash
> mdt.audiodb-MDT0000.root_squash=0:1
> 0 edi-vf-1-5:audiodb-MDT0000# lctl set_param mdt.audiodb-MDT0000.root_squash="0:0"
> mdt.audiodb-MDT0000.root_squash=0:0
> # Using the documented version.
> 0 edi-vf-1-5:audiodb-MDT0000# lctl set_param audiodb.mdt.root_squash="0:1"
> error: set_param: param_path 'audiodb/mdt/root_squash': No such file or directory
> 0 edi-vf-1-5:audiodb-MDT0000#
> Snip---
>  
> Yours
> Faye Gibbins
> Snr SysAdmin, Unix Lead Architect
> Software Systems and Cloud Services
> Cirrus Logic | cirrus.com  | +44 (0) 131 272 7398
>  
> <image001.png>
>  
> This message and any attachments may contain privileged and confidential information that is intended solely for the person(s) to whom it is addressed. If you are not an intended recipient you must not: read; copy; distribute; discuss; take any action in or make any reliance upon the contents of this message; nor open or read any attachment. If you have received this message in error, please notify us as soon as possible on the following telephone number and destroy this message including any attachments. Thank you. Cirrus Logic International (UK) Ltd and Cirrus Logic International Semiconductor Ltd are companies registered in Scotland, with registered numbers SC089839 and SC495735 respectively. Our registered office is at 7B Nightingale Way, Quartermile, Edinburgh, EH3 9EG, UK. Tel: +44 (0)131 272 7000. cirrus.com _______________________________________________
> lustre-discuss mailing list
> lustre-discuss at lists.lustre.org
> http://lists.lustre.org/listinfo.cgi/lustre-discuss-lustre.org

Cheers, Andreas
--
Andreas Dilger
Lustre Principal Architect
Intel Corporation