My setup is a little different in that at the moment I have 2 I/O
services
running on one box, a metadata on another and a client/samba server on a
third. I have moved in the data via samba. We have copied in mp3's and
avi/mpg's as well as large ISO's plus software exe's. Surely after
several
week of use we would notice some problem ?
I do have another box set up as a client that happens to have a dvd ROM
drive in it.
What type of files ? A vob ?
What sequence of commands would I need to do you test your problem ?
If I get a little spare time I could try for U ?
Steve
-------Original Message-------
From: Mark Van De Vyver
Date: 02/03/2007 08:18:11
To: Steve
Subject: Re: [Pvfs2-users] PVFS 2.6.2 intermittent cmp/diff failure
Hi Steve,
> Not sure if this helps any but I have copied over 500gb of media
files to
> pvfs2 running on old dell's 533 to 866 CPU with very little ram
running on
> caos3 beta 3. Although I havent done any checks other than using the
media
> I havent noticed any problems.
>
The failures might be spurious....?
> Could you have problems with the dvd device ?
I doubt it - but it may not be impossible?
This happens with the DVD drives on all three nodes, and when I just
Have one node 'working the diif/cmp failures either don't occur or
Very, very rarely. Start all three nodes 'working' and I see roughly
1 out of 2 binary files fail the initial diff/cmp check, but very very
Few (one every couple of DVD's fail the cmp/diff check immediately
After the copy is done.....
Thanks
Mark
>
> -------Original Message-------
>
>
>
> From: Mark Van De Vyver
>
> Date: 02/03/2007 03:26:40
>
> To: [email protected]
>
> Subject: [Pvfs2-users] PVFS 2.6.2 intermittent cmp/diff failure
>
>
>
> Hi,
>
> This is a follow up on an earlier email where I reported that PVFS
>
> 1.5.1 failed copy binary files from several DVD's.
>
>
>
> I'm running a 3 node Rocks 4.2.1 Cluster, CentOS4.4, x86_64, nodes are
>
> Connected via an unmanaged switch.
>
>
>
> I have reinstalled the Rocks Cluster (all nodes), including the
PVFS2 Roll
>
> The cluster is set up with the frontend as the metadaat server and the
>
> Other two nodes are PVFS2 I/O servers and clients. The /mnt.pvfs2
>
> Area is on a 3 disk RAID 0 partition formatted as ext3.
>
> After installing I ran the test steps in the "PVFS2 Quick Start
>
> Guide". The test steps ran without error.
>
> I upgraded to PVFS 2.6.2 on all nodes and re-ran the test steps, again
>
> No errors or problems.
>
>
>
> I build PVFS 2.6.2 with the following:
>
>
>
> ./configure --with-kernel=</path/to/kernel26/>
>
> --enable-kernel-sendfile --prefix=/usr/local/pvfs2/
>
> Then type
>
> Make all
>
> Make kmod_install
>
> Make install
>
>
>
> On each node I have a script that lists the files on the DVD disc
>
> Loaded on that node.
>
> Each file is copied if it does not exist on the HDD (PVFS area) and
>
> The copy is immediately verified:
>
>
>
> Cp /dvd/file1 /mnt/pvfs2/file1
>
> Cmp /dvd/file1 /mnt/pvfs2/file1
>
>
>
> `cmp` does not report any error.
>
> This has been done for 60-70 DVD.
>
>
>
> If I insert a DVD that has previously been copied my script finds that
>
> A file exists in the PVFS area and does a `cmp` with the DVD file, if
>
> The file fails this comparison the file is deleted, copied, verified
>
> (cmp).
>
>
>
> I notice that frequently and randomly the previously copied files will
>
> Fail the _initial_ `cmp` check if more than one node is 'active', I.e.
>
> Processing a DVD.
>
> Once deleted and copied the second `cmp` check is passed.
>
>
>
> Some details:
>
> The files do not fail the `cmp` check immediately after being copied -
>
> Only when checking a previously copied file.
>
> The `cmp` result indicates a different byte at which the files differ.
>
> Re-inserting the same dvd several times results if different files
>
> Failing the first `cmp` check.
>
> The second check (immediately after the copy is finished) is always
passed
>
> This occurs rarely, if at all (I.e. I haven't noticed it), when only
>
> One node is processing a DVD.
>
> This only occurs with binary files - which are relatively large
200MB - 2
GB
>
>
> This never occurs with text files - which are also small 100'sKB
>
> The pvfs2-client.log file is empty on each node.
>
> I have tried using diff and experience the same results.
>
>
>
> This is similar to an error I was seeing in PVFS 1.5.1 - hence the
>
> Upgrade. I've also changed my previous script which `dd` copied the
>
> DVD to memory (approx 8GB), then wrote this ISO file to the PVFS2 area
>
> - this worked fine for initial copies, but failed for re-copies. At
>
> That time I wasn't verifiying the copy, so it was the copy to the
>
> PVFS2 area that failed.....
>
>
>
> Finally, on one occasion when manually running `cmp` on a file I
>
> Noticed the following sequence.
>
> Cmp file1 file2 (pass)
>
> Cmp file1 file2 (pass)
>
> Difffile1 file2 (fail)
>
> Cmp file1 file2 (fail)
>
>
>
> Is this known behavior with a known workaround/configuration setting?
>
> The behavior I see made me guess a caching or network issue (there are
>
> No other machines on the cluster network).
>
> Can anyone suggest PVFS configuration settings that will make PVFS more
> robust.
>
>
>
> I'm not a programmer or linux guru - I just spent this summer
>
> Converting from winxp...
>
> I'm happy to explore some possible fixes, but don't assume too much :)
>
>
>
> Thanks in advance
>
> Mark
>
> _______________________________________________
>
> Pvfs2-users mailing list
>
> [email protected]
>
> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
>
>
>
