[Pvfs2-users] Problem with restarting pvfs on a cluster

Giammanco Raimondo giamma at vki.ac.be
Thu Oct 11 03:04:28 EDT 2007


Hello Mr. Lang,

 well, the mystery  is not lifted yet. I got a hold unexpectedly of the 
previous admin, and indeed it seems there is something
wrong with the machine. There is a secondary hard-disk that he had put 
under lvm that is not responding anymore:
fdisk reports problem with the partition table, and no logical volumes 
are found by the lvm tools.

 Is this the problem? I do not know. It never occurred to me that there 
could be another hd since there was
no mention in the fstab. So maybe a flying mount... Strange. But 
stranger still is the timestamp of the directory
in the pvfs2-storage-space in the master..

 I had a joint screen session with the previous admin yesterday as I 
said, but the problem, namely
recovering this lvm setup was not resolved. I hope to be able to have 
him help me again,
I will keep you informed on the progress.

Thanks again.

Raimondo
Sam Lang wrote:
>
> On Oct 10, 2007, at 3:51 AM, Raimondo Giammanco wrote:
>
>> Hello Mr. Lang,
>>
>> As far as I understand, on the master /pvfs2-storage-space is
>> not a mount point. /etc/fstab has no mention of it,
>> and the directory it contains (744468fe) has a timestamp
>> that is relative to the  day we had to shutdown the master, so
>> I cannot think that there was something mounted there..
>>
>> So, I am fairly certain /pvfs2-storage-space on the master was
>> related to the metadata, but it is empty.
>
> Hi Raimondo,
>
> Somehow then a number of files in your storage space on the master 
> have gone missing.  Without them, you won't be able to start that 
> server, and you will have to recreate the storage space (destroying 
> the files that were there).  I'm a little skeptical that the files 
> just vanished (it looks like they were deleted somehow), which is why 
> I suggested the storage space might not be mounted properly.  Do you 
> get anything interesting when you run fsck on /dev/sda1?  What 
> raid-level was used for the raid device?
>
> I guess the big question is whether you can just ask the person you 
> inherited administration from what the setup was before.  That would 
> save us a lot of trouble trying to figure it out post-mortem.
>
> -sam
>
>
>>
>> If I were to initialize it with the -f option, would after 
>> reconstruct the data from the
>> IO nodes, were all seems correct and the pvfs2-server process started 
>> correctly?
>>
>> This seems rather risky to me.
>>
>> Thanks for your help.
>>
>> Raimondo
>>
>>
>> Sam Lang wrote:
>>>
>>> On Oct 9, 2007, at 12:57 PM, Raimondo Giammanco wrote:
>>>
>>>> Hello Mr. Lang,
>>>>
>>>>  the master is a different unit type, different from the nodes that 
>>>> are
>>>> blades in a rack mounted cluster.
>>>>
>>>> The mount command provides on the master:
>>>> ##################
>>>> /dev/sda1 on / type ext3 (rw)
>>>> none on /proc type proc (rw)
>>>> none on /sys type sysfs (rw)
>>>> none on /dev/pts type devpts (rw,gid=5,mode=620)
>>>> usbfs on /proc/bus/usb type usbfs (rw)
>>>> none on /dev/shm type tmpfs (rw)
>>>> none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
>>>> sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
>>>> nfsd on /proc/fs/nfsd type nfsd (rw)
>>>> ##################
>>>>
>>>>
>>>> while on the node it is
>>>> ##################
>>>> /dev/ram0 on / type ext2 (rw)
>>>> none on /proc type proc (rw)
>>>> none on /sys type sysfs (rw)
>>>> none on /dev/pts type devpts (rw,gid=5,mode=620)
>>>> usbfs on /proc/bus/usb type usbfs (rw)
>>>> none on /dev/shm type tmpfs (rw)
>>>> /dev/md0 on /tmp type ext3 (rw)
>>>> /dev/md1 on /pvfs2-storage-space type ext3 (rw)
>>>> none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
>>>> sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
>>>> 10.0.0.254:/home on /home type nfs (rw,addr=10.0.0.254)
>>>> 10.0.0.254:/usr on /usr type nfs (rw,addr=10.0.0.254)
>>>> 10.0.0.254:/opt on /opt type nfs (rw,addr=10.0.0.254)
>>>> nfsd on /proc/fs/nfsd type nfsd (rw)
>>>> #####################
>>>>
>>>>
>>>> The difference is, I believe, that the master has a hardware raid,
>>>
>>> Is the hardware raid /dev/sda1 mounted to / ?  If not, maybe the 
>>> hardware raid on the master needs to be mounted to 
>>> /pvfs2-storage-space?
>>>
>>>> while the nodes have 2 small hd in software raid for the system and
>>>> temporary data, and 2 big ones, still in software raid, for pvfs.
>>>
>>> Ok that explains the lost+found.  FYI, while the 
>>> /pvfs2-storage-space may exist as a directory in /, it can also be a 
>>> mountpoint for something else, so its contents may not be visible 
>>> (at least the contents you would expect) if you haven't mounted 
>>> everything properly.
>>>
>>> -sam
>>>
>>>>
>>>> Regards,
>>>> Raimondo
>>>>
>>>>
>>>>>
>>>>> On Oct 9, 2007, at 9:40 AM, Giammanco Raimondo wrote:
>>>>>
>>>>>> Hello Mr. Ross,
>>>>>>
>>>>>> thanks for your prompt reply.
>>>>>>
>>>>>> I believe the config file you mention is (for my case)  /etc/pvfs2-
>>>>>> server.conf-master-pvfs.
>>>>>> its contents are:
>>>>>> ############################
>>>>>> StorageSpace /pvfs2-storage-space
>>>>>> HostID "tcp://master-pvfs:3334"
>>>>>> LogFile /tmp/pvfs2-server.log
>>>>>> ############################
>>>>>>
>>>>>> The config file for a node, /etc/pvfs2-server.conf-node1-pvfs for
>>>>>> example, is the following:
>>>>>> ############################
>>>>>> StorageSpace /pvfs2-storage-space
>>>>>> HostID "tcp://node1-pvfs:3334"
>>>>>> LogFile /tmp/pvfs2-server.log
>>>>>> ############################
>>>>>>
>>>>>> Now, this /pvfs2-storage-space is unfortunately directly on the /,
>>>>>> so the wrong
>>>>>> mount timing theory is unfortunately to discard.
>>>>>
>>>>> In the directory listing you gave us for node1 /pvfs2-storage-space,
>>>>> there's a lost+found directory.  That only appears if you've mounted
>>>>> another volume into that directory.  My guess is that for the master
>>>>> node, you've managed to somehow create part of the storage space
>>>>> before mounting something to /pvfs2-storage-space, and the rest was
>>>>> created after.  You're only seeing what was created before the
>>>>> mount.  That's just a guess though.  Can you send us the output of
>>>>> 'mount' on node1 and master?
>>>>>
>>>>> -sam
>>>>>
>>>>>>
>>>>>> On the nodes instead /pvfs2-storage-space it is on a mounted
>>>>>> filesystem, /dev/md1,
>>>>>> but there all goes apparently right, so it seems to me that really
>>>>>> there is a problem
>>>>>> with the master node and metadata server.
>>>>>>
>>>>>> The suggestion given by the log of pvfs2-server binary of using the
>>>>>> -f option looks
>>>>>> very dangerous to me, or in case of the metadata server it is ok,
>>>>>> in the sense that
>>>>>> it will reconstruct the data from the IO nodes? I cannot understand
>>>>>> why
>>>>>> the different storages have the same directory in common "744468fe",
>>>>>> but the master has nothing else beside this empty directory.
>>>>>>
>>>>>> Even if the pvfs2-server process had been killed in a not clean way
>>>>>> on the master and metadata server,
>>>>>> it would not have been able (I assume) to delete data on the
>>>>>> storage directory...
>>>>>>
>>>>>> So this absence of data in  /pvfs2-storage-space for the metadata
>>>>>> server is both disconcerting and confusing...
>>>>>>
>>>>>> Hope this mail will help us to proceed further.
>>>>>>
>>>>>> Best Regards
>>>>>> Raimondo
>>>>>>
>>>>>> Rob Ross wrote:
>>>>>>> Hi Raimondo,
>>>>>>>
>>>>>>> Two things. One, there is a second config file around that
>>>>>>> specifies the storage directory etc. You should be able to find it
>>>>>>> in /etc/ also. Please send that to us.
>>>>>>>
>>>>>>> An idea is that perhaps /pvfs2-storage-space is a mounted file
>>>>>>> system, and that somehow it is getting mounted *after* the server
>>>>>>> is started? Just a blind guess. If you try to start the service
>>>>>>> after the system has finished booting, does it do the same thing?
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Rob
>>>>>>>
>>>>>>> Raimondo Giammanco wrote:
>>>>>>>> Hello, there.
>>>>>>>>
>>>>>>>>  I am coming here seeking words of wisdom. I have looked the
>>>>>>>> interweb and
>>>>>>>> this list but I cannot seem to find useful informations, so I
>>>>>>>> post here.
>>>>>>>> I apologize if the answer to the question has already been
>>>>>>>> provided and I
>>>>>>>> could not find it.
>>>>>>>>
>>>>>>>> I have a problem with a pvfs2 installation that has been set-up
>>>>>>>> by a third
>>>>>>>> person. The cluster has been shutdown cleanly for a scheduled
>>>>>>>> maintenance
>>>>>>>> on the power lines, and I cannot bring pvfs2 up again.
>>>>>>>>
>>>>>>>> Here is the description.
>>>>>>>>
>>>>>>>> There is a cluster using a fronted and 9 nodes.
>>>>>>>>
>>>>>>>> As far as I understand, the fronted is a metadata server, and the
>>>>>>>> nodes
>>>>>>>> are IO servers, as for the /etc/pvfs2-fs.conf file I present here
>>>>>>>> below:
>>>>>>>>
>>>>>>>> ####################
>>>>>>>> <Defaults>
>>>>>>>>         UnexpectedRequests 50
>>>>>>>>         EventLogging none
>>>>>>>>         LogStamp datetime
>>>>>>>>         BMIModules bmi_tcp
>>>>>>>>         FlowModules flowproto_multiqueue
>>>>>>>>         PerfUpdateInterval 1000
>>>>>>>>         ServerJobBMITimeoutSecs 30
>>>>>>>>         ServerJobFlowTimeoutSecs 30
>>>>>>>>         ClientJobBMITimeoutSecs 300
>>>>>>>>         ClientJobFlowTimeoutSecs 300
>>>>>>>>         ClientRetryLimit 5
>>>>>>>>         ClientRetryDelayMilliSecs 2000
>>>>>>>> </Defaults>
>>>>>>>>
>>>>>>>> <Aliases>
>>>>>>>>         Alias master-pvfs tcp://master-pvfs:3334
>>>>>>>>         Alias node1-pvfs tcp://node1-pvfs:3334
>>>>>>>>         Alias node2-pvfs tcp://node2-pvfs:3334
>>>>>>>>         Alias node3-pvfs tcp://node3-pvfs:3334
>>>>>>>>         Alias node4-pvfs tcp://node4-pvfs:3334
>>>>>>>>         Alias node5-pvfs tcp://node5-pvfs:3334
>>>>>>>>         Alias node6-pvfs tcp://node6-pvfs:3334
>>>>>>>>         Alias node7-pvfs tcp://node7-pvfs:3334
>>>>>>>>         Alias node8-pvfs tcp://node8-pvfs:3334
>>>>>>>>         Alias node9-pvfs tcp://node9-pvfs:3334
>>>>>>>> </Aliases>
>>>>>>>>
>>>>>>>> <Filesystem>
>>>>>>>>         Name pvfs2-fs
>>>>>>>>         ID 1950640382
>>>>>>>>         RootHandle 1048576
>>>>>>>>         <MetaHandleRanges>
>>>>>>>>                 Range master-pvfs 4-429496732
>>>>>>>>         </MetaHandleRanges>
>>>>>>>>         <DataHandleRanges>
>>>>>>>>                 Range node1-pvfs 429496733-858993461
>>>>>>>>                 Range node2-pvfs 858993462-1288490190
>>>>>>>>                 Range node3-pvfs 1288490191-1717986919
>>>>>>>>                 Range node4-pvfs 1717986920-2147483648
>>>>>>>>                 Range node5-pvfs 2147483649-2576980377
>>>>>>>>                 Range node6-pvfs 2576980378-3006477106
>>>>>>>>                 Range node7-pvfs 3006477107-3435973835
>>>>>>>>                 Range node8-pvfs 3435973836-3865470564
>>>>>>>>                 Range node9-pvfs 3865470565-4294967293
>>>>>>>>         </DataHandleRanges>
>>>>>>>>         <StorageHints>
>>>>>>>>                 TroveSyncMeta yes
>>>>>>>>                 TroveSyncData no
>>>>>>>>         </StorageHints>
>>>>>>>> </Filesystem>
>>>>>>>> ####################
>>>>>>>>
>>>>>>>> The nodes are apparently working correctly, at boot the /etc/
>>>>>>>> init.d/pvfs2
>>>>>>>> script worked and the log file (/tmp/pvfs2-server.log) gives me
>>>>>>>> for a
>>>>>>>> node:
>>>>>>>> ####################
>>>>>>>> [D 10/08 14:39] PVFS2 Server version 2.6.2 starting.
>>>>>>>> ####################
>>>>>>>>
>>>>>>>> on the master instead, it gives
>>>>>>>> ####################
>>>>>>>> [D 10/09 11:09] PVFS2 Server version 2.6.2 starting.
>>>>>>>> [E 10/09 11:09] Error: trove_initialize: No such file or directory
>>>>>>>> [E 10/09 11:09]
>>>>>>>> ***********************************************
>>>>>>>> [E 10/09 11:09] Invalid Storage Space: /pvfs2-storage-space
>>>>>>>>
>>>>>>>> [E 10/09 11:09] Storage initialization failed.  The most common
>>>>>>>> reason
>>>>>>>> for this is that the storage space has not yet been
>>>>>>>> created or is located on a partition that has not yet
>>>>>>>> been mounted.  If you'd like to create the storage space,
>>>>>>>> re-run this program with a -f option.
>>>>>>>> [E 10/09 11:09]
>>>>>>>> ***********************************************
>>>>>>>> [E 10/09 11:09] Error: Could not initialize server interfaces;
>>>>>>>> aborting.
>>>>>>>> [E 10/09 11:09] Error: Could not initialize server; aborting.
>>>>>>>> ####################
>>>>>>>>
>>>>>>>> Now, the storage space on the nodes is full:
>>>>>>>> ####################
>>>>>>>> [root at node1 ~]# ls /pvfs2-storage-space/
>>>>>>>> 744468fe  collections.db  lost+found  storage_attributes.db
>>>>>>>> ####################
>>>>>>>> on the master (frontend) not:
>>>>>>>> ####################
>>>>>>>> [root at master ~]# ls /pvfs2-storage-space/
>>>>>>>> 744468fe
>>>>>>>> ####################
>>>>>>>>
>>>>>>>> Anyone can point me in the right direction?
>>>>>>>>
>>>>>>>> Thanks Again
>>>>>>>>
>>>>>>>> Raimondo
>>>>>>>> _______________________________________________
>>>>>>>> Pvfs2-users mailing list
>>>>>>>> Pvfs2-users at beowulf-underground.org
>>>>>>>> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
>>>>>>>>
>>>>>>
>>>>>> <giamma.vcf>
>>>>>> _______________________________________________
>>>>>> Pvfs2-users mailing list
>>>>>> Pvfs2-users at beowulf-underground.org
>>>>>> http://www.beowulf-underground.org/mailman/listinfo/pvfs2-users
>>>>>
>>>>
>>>>
>>
>>

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