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>A customer is planning how their data of a critical system
>could be stored using Advfs. He is planning to use Digital
>Unix 4.0b. He has the following conditions:
>
>1) Each of the data directory would be required to
> store more than 200,000 files.
ok, you want plenty of memory, and up the size of the advfs cache
in /etc/sysconfigtab
>
>2) Most of the data files are small (less than 1K) and
> the size is not fixed
>
>3) He said the files under a data directory will be removed
> regularly (per month). This may create a large extent of
> fragmentation.
I would initially size the BMT for the number of files
to be in the domain.
To prevent the fragmentation, run defragment regularly, and ensure
plenty of disk space. I would suggest multiple domains, each
with multiple volumes of 10GB or less...
ensure you have free disks (of volume size) for addvol/rmvol
>
>4) Each file will have a very long file name.
>
>
>In order to aid his planning, he is asking for the different
>aspects of resource limitations of Advfs.
>
>a) Is there any maximum value that limit the number of files
> to be stored under a single directory?
Just a performance question, assuming you run defragment
regularly. The memory will help...or spread out over more
directories...
>
>b) If the answer of a) is NO regarding a single directory alone.
> What are the other resources limitation that he should consider
> for his case?
memory
>
> e.g. How could he plan and evaluate the requirement of BMT size?
How many files per domain is the issue for the BMT size. If the
files are small, and you run defragment regularly, this should
be able to be stable over time once you hit steady state.
Don't overfill the disks to avoid BMT fragmentation...
>
>
>c) What is the maximum length of a file name under Advfs?
same as Digital unix.
>
>
>d) Would the large extent of fragmentation cause problems
> for Adfvs?
if you run defragment, the fragmentation should not be
an issue (and you don't run the disks to 0 free space).
>
>e) Also any limit on maximum number of file domains in a system?
listed in the OS limits (release notes, or technical overview...)
I think it is 256 or 512 domains a system if I recall...
>
>
>Grateful for any help
>
>- Feynman
>
>
>[Posted by WWW Notes gateway]
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