This Article is only for Netbackup 7.5 version which uses Linux as operation system for example SLES 11 or RHEL.
When you using the SLP or Vault Feature in NetBackup you can see a lot of issues like those:
failed, media read error (85). cannot position to correct image (94) with error 84 (media write error)
In the last week / month I had a lot of the above issue and tried to look in each of them. From the first view it looks like those errors are not really related or will have a same simple resolution, but they does.
Please be aware that I don’t want to tell that the below mentioned Steps are always resolving this issues, but this is a good Step to start. All those settings are related to the OS in this Case Linux and should help in big Environments to resolve issue like above, when it is seen very often. Those values can be setup different on each master server, where you should fine the best settings for you Environment.
So the file we are talking is the /etc/security/limits.conf which comes by a SLES installation without any values as they are all uncommented. This can dependence again on which Linux distribution you are using.
So this will give us the default values like for example mine:
core file size
(blocks, -c) 1
data seg size
(kbytes, -d) unlimited
(blocks, -f) unlimited
max locked memory
(kbytes, -l) 64
max memory size
(kbytes, -m) 3334548
(512 bytes, -p) 8
POSIX message queues
(bytes, -q) 819200
(kbytes, -s) 8192
(seconds, -t) unlimited
max user processes
(kbytes, -v) 4821040
The open files value is definitive too small for a big Environment and can cause all the above issues. The Master Server is the main part in the Backup Environment and depending on the size of the Environment (Media Server, Clients etc.) the limit from 1000 will be reached very fast. As for me the Errors I got always looked different or I used different settings (vault and SLP) I didn’t believe that this will solve all of those issue. But I gave it a try and used the Symantec recommended values from the following Technote:
After I had this values and rebooted the server all the above errors was resolved. For sure it will not resolve those issues in all environment, but it is an easy way to check, before starting the deep troubleshooting.