Perl cannot copy from a HSM archive

[jez]

Hi everyone,

I am trying to copy files from a HSM archive. They appear as stub files but give name and size correctly.

When i then try and copy it fails with 'no such file or directory'. This only happens on files that are not cached, for instance if i try and copy it fails, then i try on the same file and it works (as it is cached), then an archive file-fail, etc

I have tried 'File::Copy', 'File::Copy::syscopy', system(copy ..)

Yet none of them seem to be able to deal with the delay in copying from blue ray disk back to spinning disk.

Has anyone got any ideas?


Jez

 

[Annihilannic]

Does it not happen with any other system utilities, such as cp? If not, why not... are they special versions designed to cope with the HSM archive or something?

As a clunky workaround you could just retry each copy if the initial one fails...

Annihilannic.

 

[stevexff]

On z/OS HSM hooks in to an exit point in the open/close routines and hence becomes almost part of the OS. So an open of an HSM file just causes a wait while it stages it onto 'real' disk.

Annihilannic may be right - maybe you need to build Perl on your system so it can link the tweaked HSM open/close routines? Try his suggestion about cp - in the worst case you could always just shell out to cp. Alternatively, you could use HSM to determine if the file is in the cache, and if not then explicitly recall it.

Steve

[small]"Every program can be reduced by one instruction, and every program has at least one bug. Therefore, any program can be reduced to one instruction which doesn't work." (Object:erlDesignPatterns)[/small]

 

[jez]

Thanks for the suggestions.

Since posting here i have tried to use only system commands such as "cp" to do the copy, this is to make sure that there is no different failure with or without perl.

The problems i have had continued, but i have tracked them back to a poorly performing NetApp SAN, which is acting like a local disk on the HSM for caching incoming and outgoing files, due to the load on this SAN it does sometimes drop connections half way through a read. This is tricky to find when there is supposed to no network stuff going on, but it seems to be the only explanation for the symptoms.

Thanks for the suggestions.