https://jira.whamcloud.com This file is an XML representation of an issue en-us 9.4.14 940014 05-12-2023 https://jira.whamcloud.com/browse/LU-1256 Lustre <p>I have a few questions about Checksums.</p> <p>Section 19.5.1 of the manual says:</p> <p> To check the status of a wire checksum, run:</p> <p> lctl get_param osc.*.checksums</p> <p>Does that mean that clearing this parameter only clears the wire checksum?</p> <p>Does writing each file named /proc/fs/lustre/osc/*/checksums do the same thing?</p> <p>Is there a way to permanently disable checksums?</p> <p>Thanks.</p> LU-1256

Question about checksums

Improvement Minor Resolved Fixed Cliff White Roger Spellman Fri, 23 Mar 2012 14:31:36 +0000 Tue, 17 Apr 2012 14:10:23 +0000 Tue, 17 Apr 2012 14:10:23 +0000 Lustre 2.1.0 0 1 <p>Cliff</p> <p>Could you please help out with this one?</p> <p>Thanks</p> <p>Peter</p> <p>Are you using the current Lustre manual? I am checking the 2.0 manual, per 19.5.1. <br/> Does seem to be a bit unclear, perhaps should be rewritten. </p> <p>First, in general, the old way of parameter access is directly to the /proc files, the new<br/> modern way is using get/set commands, if the path is the same both (atm) should do the same thing, but the get/set method<br/> is future-compatible. You should be able to set a persistent value with lctl conf_param.</p> <p>Both types of checksums are controlled by "lctl set_param llite.*.checksum_pages" which is a client-only parameter. </p> <p>Network (wire) checksums can be set/unset with the osc.*.checksums parameter. This is done per-client and per ost connection.<br/> Again, you can set/get with lctl or by direct file access. </p> <p>So, you can have network and memory checksums, or memory only, or none. </p> <p>Thanks, Cliff.</p> <p>Is there a way to permanently disable checksums?</p> <p>There is CRC on the wire, and ECC on the RAM.<br/> Exactly what errors are the checksums supposed to catch? </p> <p>As I said, you should be able to turn them off persistently with lctl conf_param, there is no other switch. CRC and ECC are hardware checksums, the Lustre checksums include the Lustre stack and are supposed to catch any issues in that area. </p> <p>As per Peter Piela this ticket can be closed</p> Development Rank 1|hzw02n: Rank (Obsolete) 10091