From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Price Date: Mon, 9 May 2016 16:10:19 +0100 Subject: [Cluster-devel] [PATCH] gfs2(5): add rgrplbv and loccookie info the the manpage In-Reply-To: <20160415222214.GD2988@octiron.msp.redhat.com> References: <1460738023-7874-1-git-send-email-bmarzins@redhat.com> <20160415222214.GD2988@octiron.msp.redhat.com> Message-ID: <5730A85B.6000101@redhat.com> List-Id: To: cluster-devel.redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On 15/04/16 23:22, Benjamin Marzinski wrote: > The only issue with these patches is that they are geared for upstream. > Instead of listing the 3.6 and 4.5 linux kernels, the RHEL man pages > should list the relevant rhel kernels. I suppose the easiest way to > deal with this would be to patch them in the rhel rpms. That sounds like the way to go. Looks good to me. Thanks, Andy > > -Ben > > On Fri, Apr 15, 2016 at 11:33:43AM -0500, Benjamin Marzinski wrote: >> The gfs2 man page didn't have any information about the rgrplvb and >> loccookie mount options. This patch adds it. >> >> Signed-off-by: Benjamin Marzinski >> --- >> gfs2/man/gfs2.5 | 34 ++++++++++++++++++++++++++++++++++ >> 1 file changed, 34 insertions(+) >> >> diff --git a/gfs2/man/gfs2.5 b/gfs2/man/gfs2.5 >> index 0517944..56d1a00 100644 >> --- a/gfs2/man/gfs2.5 >> +++ b/gfs2/man/gfs2.5 >> @@ -165,6 +165,40 @@ the statfs information on a local basis before it is synced back >> to the master statfs file, even if the time period has not >> expired. If the setting of statfs_quantum is 0, then this setting >> is ignored. >> +.TP >> +\fBrgrplvb\fP >> +This flag tells gfs2 to look for information about a resource group's free >> +space and unlinked inodes in its glock lock value block. This keeps gfs2 from >> +having to read in the resource group data from disk, speeding up allocations in >> +some cases. This option was added in the 3.6 Linux kernel. Prior to this >> +kernel, no information was saved to the resource group lvb. \fBNote:\fP To >> +safely turn on this option, all nodes mounting the filesystem must be running >> +at least a 3.6 Linux kernel. If any nodes had previously mounted the filesystem >> +using older kernels, the filesystem must be unmounted on all nodes before it >> +can be mounted with this option enabled. This option does not need to be >> +enabled on all nodes using a filesystem. >> +.TP >> +\fBloccookie\fP >> +This flag tells gfs2 to use location based readdir cookies, instead of its >> +usual filename hash readdir cookies. The filename hash cookies are not >> +guaranteed to be unique, and as the number of files in a directory increases, >> +so does the likelihood of a collision. NFS requires readdir cookies to be >> +unique, which can cause problems with very large directories (over 100,000 >> +files). With this flag set, gfs2 will try to give out location based cookies. >> +Since the cookie is 31 bits, gfs2 will eventually run out of unique cookies, >> +and will fail back to using hash cookies. The maximum number of files that >> +could have unique location cookies assuming perfectly even hashing and names of >> +8 or fewer characters is 1,073,741,824. An average directory should be able to >> +give out well over half a billion location based cookies. This option was added >> +in the 4.5 Linux kernel. Prior to this kernel, gfs2 did not add directory >> +entries in a way that allowed it to use location based readdir cookies. >> +\fBNote:\fP To safely turn on this option, all nodes mounting the filesystem >> +must be running at least a 4.5 Linux kernel. If this option is only enabled on >> +some of the nodes mounting a filesystem, the cookies returned by nodes using >> +this option will not be valid on nodes that are not using this option, and vice >> +versa. Finally, when first enabling this option on a filesystem that had been >> +previously mounted without it, you must make sure that there are no outstanding >> +cookies being cached by other software, such as NFS. >> >> .SH BUGS >> >> -- >> 2.1.0 >