Kjournald

SpiffyJr

<div class="IPBDescription">what is it and can i stop it!</div> Okay, currently running RH 8.0. Periodically my server's been getting some horrid lag spikes for a few minutes or so. Was never around to actualy see what was going on so I couldn't check it. Tonight it started spiking and I ran top to see what the deal was. CPU usage was at a 100 percent but only because kjournald was hogging all the extra causing an increase in pings. Being as how I've only been working with linux a few months and I've lots to learn, would someone enlighten me on what kjournald is and whether or not it's able to shut it down? Thanks in advance.

verbose

<!--QuoteBegin--SpiffyJr+Feb 6 2003, 06:16 PM--></span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> (SpiffyJr @ Feb 6 2003, 06:16 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin--> Okay, currently running RH 8.0. Periodically my server's been getting some horrid lag spikes for a few minutes or so. Was never around to actualy see what was going on so I couldn't check it. Tonight it started spiking and I ran top to see what the deal was. CPU usage was at a 100 percent but only because kjournald was hogging all the extra causing an increase in pings. Being as how I've only been working with linux a few months and I've lots to learn, would someone enlighten me on what kjournald is and whether or not it's able to shut it down? Thanks in advance. <!--QuoteEnd--> </td></tr></table><span class='postcolor'> <!--QuoteEEnd-->
kjournald is part of the ext-3 journalling file system.

Here's a place to start: <a href='http://www.redhat.com/mailing-lists/ext3-users/msg08866.html' target='_blank'>http://www.redhat.com/mailing-lists/ext3-u...s/msg08866.html</a>

cracker_jackmac

aka DON'T KILL IT OFF


its kinda important

Kjournald

K stands for kernel.

jounal is its function

d means daemon.

verbose

I have very little experience with ext3, but I believe there's a graceful way to disable the disk journalling. You'll lose a bit of reliability, should the power fail or something. However, it shouldn't be using the amount of resources you say it is, so something is misconfigured or suboptimally configured.

cracker_jackmac

you have something hammering the disk...because i run ext3 and i never have that problem. What are you running? is your logging misconfigured? running stats? mysql?

Epoch

My server uses resierfs partitions and I have never had any problems with the journaling system. I don't know much about ext3 but resier works quite well for me.

cracker_jackmac

<!--QuoteBegin--Epoch+Feb 6 2003, 09:57 PM--></span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> (Epoch @ Feb 6 2003, 09:57 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin--> My server uses resierfs partitions and I have never had any problems with the journaling system. I don't know much about ext3 but resier works quite well for me. <!--QuoteEnd--> </td></tr></table><span class='postcolor'> <!--QuoteEEnd-->
reiserFS is sweet if you get the patches for it. 2.4.20 i think has it in it already...i don't remember.

but 2.4.18 it was still experimental (or whatever)

XFS is coooool too. but i haven't tried it yet...i don't have a High Performance Raid to beat it against.

SpiffyJr

Only thing running on the server is hlds, hlstats, and mysql. That's about it. Last time I checked kjournald jumped up to 40% cpu usage on my AMX XP 1900+.

cracker_jackmac

play with tune2fs (i think thats it) if that doesn' help......turn off hlstats (the script, not the webpage).


whats your inode size? 1024, 2048, or 4096? if its smaller than 4096 your asking for trouble...and that could cause massive journal commits

SpiffyJr

tune2eh? inode what? I haven't been using linux that long... little help <!--emo&:0--><img src='http://www.unknownworlds.com/forums/html/emoticons/wow.gif' border='0' style='vertical-align:middle' alt='wow.gif'><!--endemo-->

verbose

<!--QuoteBegin--SpiffyJr+Feb 7 2003, 01:47 PM--></span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> (SpiffyJr @ Feb 7 2003, 01:47 PM)</td></tr><tr><td id='QUOTE'><!--QuoteEBegin--> tune2eh? inode what? I haven't been using linux that long... little help <!--emo&:0--><img src='http://www.unknownworlds.com/forums/html/emoticons/wow.gif' border='0' style='vertical-align:middle' alt='wow.gif'><!--endemo--> <!--QuoteEnd--> </td></tr></table><span class='postcolor'> <!--QuoteEEnd-->
He mistyped. He meant to say "install Debian", but missed a few characters <!--emo&:p--><img src='http://www.unknownworlds.com/forums/html/emoticons/tounge.gif' border='0' style='vertical-align:middle' alt='tounge.gif'><!--endemo-->

ext3 is out of my realm of expertise, so I shall leave this thread to those more experienced.

cracker_jackmac

man tune2fs

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<!--QuoteBegin--></span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td><b>QUOTE</b> </td></tr><tr><td id='QUOTE'><!--QuoteEBegin-->      -J journal-options
              Override the default ext3 journal parameters. Jour-
              nal options are comma separated, and  may  take  an
              argument using the equals ('=')  sign.  The follow-
              ing journal options are supported:

                  size=journal-size
                          Create a journal stored in the filesys-
                          tem  of  size  journal-size  megabytes.
                          The size of  the  journal  must  be  at
              argument using the equals ('=')  sign.  The follow-
              ing journal options are supported:

                  size=journal-size
                          Create a journal stored in the filesys-
                          tem  of  size  journal-size  megabytes.
                          The size of  the  journal  must  be  at
                          least 1024 filesystem blocks (i.e., 1MB
                          if using 1k blocks,  4MB  if  using  4k
                          blocks,  etc.)  and may be no more than
                          102,400 filesystem blocks.  There  must
                          be  enough free space in the filesystem
                          to create a journal of that size.

                  device=external-journal
                          Attach the filesystem  to  the  journal
                          block  device located on external-jour-
                          nal.  The external  journal  must  have
                          been already created using the command

                          mke2fs -O journal_dev external-journal

                          Note that external-journal must be for-
                          matted with  the  same  block  size  as
                          filesystems which will be using it.

                          Instead  of  specifying  a  device name
                          directly, external-journal can also  be
                          specified  by  either  LABEL=label  or
                          UUID=UUID to locate the external  jour-
                          nal  by either the volume label or UUID
                          stored in the ext2  superblock  at  the
                          start  of the journal.  Use dumpe2fs(8)
                          to display a  journal  device's  volume
                          label and UUID.  See also the -L option
                          of tune2fs(8).

              Only one of the size or device options can be given
              for a filesystem.
<!--QuoteEnd--></td></tr></table><span class='postcolor'><!--QuoteEEnd-->

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