Thanks, John. 

Regards, 
Richard Schuh 

 

> -----Original Message-----
> From: The IBM z/VM Operating System 
> [mailto:[EMAIL PROTECTED] On Behalf Of John Franciscovich
> Sent: Wednesday, April 09, 2008 8:45 AM
> To: [email protected]
> Subject: Re: Spool Question
> 
> >Out of curiosity, how does CP allocate spool? I notice that our 14 
> >regular spool volumes range from 43-91% used, according to Q ALLOC 
> >SPOOL. Does CP try to allocate new blocks on the least used 
> volume, or 
> >is allocation done using a rotating scheme?
> 
> Allocation of new spool blocks is not based on the least used volume.
> You could say it is done using a rotating scheme, but it is 
> certainly not a 1 for 1 rotation.
> 
> The algorithm is not straightforward or trivial, and there 
> are several factors that determine which volume a spool block 
> is allocated on.
> These range from the obvious, such as availability of space 
> on a particular volume, to less obvious and less predictable, 
> such as how many recent allocations (not a fixed number) have 
> been done on a volume.
> The boundaries which trigger switching to a different volume 
> are not fixed, but are based on the size, type, and number of 
> volumes containing spool space.
> 
> John Franciscovich
> z/VM Development
> 

Reply via email to