I think, you are the first person I have every seen who has stated it is probably not NBU ...
You are most likely correct, the issue will not likely be NBU.
I am sure there is a case or two somewhere, where status 24 has been due to NBU somehow, but in 5 years, and doing quite a few status 24 cases I have never seen it caused by NBU, and searching the database, I have never found a status 24 casued by NBU.
The problem with 24s in general, is that most people, but NOT your good self, believe that as the NBU has very politely informed you that there is some issue, it must be the fault of NBU.
The problem from our side, is that as we didn't cause the fault we can't really tell you what did - yes we know the network failed, but not why.
I will however try and be at least slightly helpful.
1. You say the issue got fixed, do you know what was done to fix it
2. I presume this was working previously
3. Is it all clients, just one client, clients on a certain network, clients on a certain OS, clients that have just been patched etc ... If you can narrow it down to a group it helps, a lot
4. If it is a single client, big bonus, as it's most likely something on the client
5. Does it always fail after approx 12 mins
6. Is any data backed up
7. Is it a certain filesystem that always fails
8. Does it fail after a certain amount of data backed up
9. Any recent changes
10. Any firewalls involved
Customers generally hate questions - but asking the right questions, and ensuring you get exactly the correct answers at the right level of detail very often provides a very big step in the solution, and sometimes even provides a solution.
The way I look at issues is I try to blame NBU - however in this case I honestly don;t know a way to make NBU fail with a 24. We do not control the network, we only use what we are given. There are a few settings (net buffer size for windows clients for example) that will certainly affect performance, but I never managed to create a 24 by changing it (and I have tried). In fact, I can't think of any other settings in NBU that 'control' the network (apart from required interface / preferred interface but these won't cause a 24).
Here are my status 24 notes ... sorry, big list but contains just about every cauuse I have seen.
In my experience, Status 24 is hardly ever NBU (in fact, I don't think I have ever seen a status 24 failure caused by NetBackup myself)
Something below normally fixes it ... Yes, it is a lot to read, and will probably tyake a number of hours to go through.
If this is a Windows client, a very common cause is the TCP Chimmey settings - http://www.symantec.com/docs/TECH55653
I have given a number of technotes below (the odd one may be 'internal' only) , and have show a summary of the solutions, as well as the odd extra note.
http://www.symantec.com/docs/TECH124766
TCP Windows scaling was disabled (Operating system setting)
http://www.symantec.com/docs/TECH76201
Possible solution to Status 24 by increasing TCP receive buffer space
http://www.symantec.com/docs/TECH34183
this Technote, although written for Solaris, shows how TCP tunings can
cause status 24s. I am sure your system admins will be aware of the
corresponding setting for the windows operating system.
http://www.symantec.com/docs/TECH55653
This technote is very important. It covers many many issues that can
occur when either TCP Chimney Offload, TCP/IP Offload Engine (TOE) or TCP
Segmentation Offload (TSO) are enabled. It is recommend to disable
these, as per the technote.
I also understand that we have previously seen MS Patch KB92222 resolve status 24 issues.
http://www.symantec.com/docs/TECH150369
A write operation to a socket failed, these are possible cause for this issue:
A high network load.
Intermittent connectivity.
Packet reordering.
Duplex Mismatch between client and master server NICs.
Small network buffer size
http://support.microsoft.com/kb/942861
SOLUTION/WORKAROUND:
Contact the hardware vendor of the NIC for the latest updates for their product as a resolution.
This problem occurs when the TCP Chimney Offload feature is enabled on the NetBackup Windows 2003 client. Disable this feature to workaround this problem.
To do this, at a command prompt, enter the following:
Netsh int ip set chimney DISABLED
http://www.symantec.com/docs/TECH127930
The above messages almost always indicate a networking issue of some sort. In this case it was due to a faulty switch. There are rare occasions when the above messages are not caused by a networking issue, such as those addressed in http://www.symantec.com/docs/TECH72115.
(TECH72115 is not relevant to you, this was an issue with a SAN client, fixed in 6.5.4)
But note, the technote says the issue is 'almost always' network related, this can also include operating system settings.
http://www.symantec.com/docs/TECH145223
The issue was with the idle timeout setting on the firewall that was too low to allow backups and/or restores to complete. With the DMZ media server backing up a DMZ client the media server sends only the occasional meta data updates back to the master server in order to update the images catalog. If that TCP socket connection between the media server and master server is idle for a longer period than the firewall's idle timeout the firewall breaks the connection between the media server and master servder and thus the media server breaks the connection to the client producing the socket error.
Increasing the idle timeout setting on the firewall to a value larger than the amount of time a typical backups takes to complete should resolve the issue.
Also increasing the frequency of the TCP keepalive packets can also help maintain the socket during idle periods from the server's defaults.
Although you may not have a firewall between the client and the media server, this solution is another demonstation that the issue is network related, as opposed to NetBackup.
http://www.symantec.com/docs/S:TECH130343 (Internal technote)
The issue was found to be due to NIC card Network congestion (that is, network overloaded)
http://www.symantec.com/docs/TECH135924 (I think this one I sent previously, shows the MS fix for the issue)
In this instance, the problem was isolated to this single machine making the point of failure isolated to the problematic new host.
If the problem is due to an unidentified corruption / misconfiguration in the new media server's TCP Stack and Winsock environment (as was the case in this example), executing these two commands, followed by a reboot will resolve the problem:
netsh int ip reset resetlog.txt Microsoft Reference: http://support.microsoft.com/kb/299357
netsh winsock reset catalog Microsoft Reference: http://technet.microsoft.com/en-us/library/cc759700(WS.10).aspx
NOTE: The above two commands will reset the Windows TCP Stack as well as the Windows Winsock environment back to the default values. This means that if the host is configured with a static IP Address and other customized TCP settings, they will be lost and will need to be re-entered after the reboot. The default TCP setting is to use DHCP and the host will be using DHCP upon booting up.
http://www.symantec.com/docs/TECH76201
Possible solution to Status 24 by increasing TCP receive buffer space
http://www.symantec.com/docs/TECH34183
this Technote, although written for Solaris, shows how TCP tunings can
cause status 24s. I am sure your system admins will be aware of the
corresponding setting for the windows operating system.
http://www.symantec.com/docs/TECH55653
This technote is very important. It covers many many issues that can
occur when either TCP Chimney Offload, TCP/IP Offload Engine (TOE) or TCP
Segmentation Offload (TSO) are enabled. It is recommend to disable
these, as per the technote.
I understand that we have previously seen MS Patch KB92222 resolve status 24 issues.
Unix/ Linux
If the error in bptm log shows :
22:32:44.968 [35717358] <16> write_to_out: cannot write data to socket, There is no process to read data written to a pipe.
Check the ulimit -a output. nofiles should be set to at least 8192.
There are 2 'common' issues that could be NBU related that could cause this :
1. Client NBU version is higher than the media serevr
2. Make sure the comunications buffer is not too high (http://www.symantec.com/docs/TECH60570
)
What to do next:
http://www.symantec.com/docs/TECH135924 (mentioned before, MS suggested fix)
http://www.symantec.com/docs/TECH60570 (communications buffer, mentioned above)
http://www.symantec.com/docs/TECH60844
If these do not resolve the situation, I would recommend you talk with the Operating system vendor. In summary, apart from the Client version of software and the communication buffer size (set in host properties) I can find no other cause that could be NBU. However, from the very detailed research I have done, I can find many many causes that are the network or operating system.
I've added my comments ...
1. You say the issue got fixed, do you know what was done to fix it
Ans: inetd was restarted on these unix hosts and it seems to be fix but it poped up again the next morning/
>> inetd restarts the network services, so I can see why it could be a potential fix (even if only temporary).
2. I presume this was working previously
Ans: Yes, the backups were working previuously but recently we moved our master server from one place to another within the data centre. The place is just adjacent to where it was before.
Moving the master server is 'common' to all the servers that fail. However, I would exepect this to have affected all the clients.
3. Is it all clients, just one client, clients on a certain network, clients on a certain OS, clients that have just been patched etc ... If you can narrow it down to a group it helps, a lot
Ans: There are around 8 clients from couple of policies and they are on two diff network. All are solaris 10 64 bit except one which is solaris 9 64 bit. 4 out of them are patched recently.
4. If it is a single client, big bonus, as it's most likely something on the client
Ans: Thera are around 8 clients. 7 from one policy and 1 from other.
>> So, not common to a single client, and not common to a single network
5. Does it always fail after approx 12 mins
Yes, since the time this issue has started approx after 5-10mins writting data.
>>It varies then which perhaps suggests it's not a timeout happening somewhere
6. Is any data backed up
Ans: Yes, the data is getting backed up when the job kicks off.
7. Is it a certain filesystem that always fails
Ans: The backup selection is ALL_LOCAL_DRIVES for all these clients.
8. Does it fail after a certain amount of data backed up
Yes, initially the data will be backed up for 5mins and later it stops and fails finally.
9. Any recent changes
Ans: Some of them are patched but not all.
10. Any firewalls involved
Ans: Not sure