Walter -
The defaults are different. So here is what I used for my sizings..
Metaback_cache_size default is 64M (depending on Meta_cache_size)
meta_cache_size 128m
vnode_cache_size 32768
user_cache_size 337m
meta_cache_size
Specifies the size of the cache used to contain metadata. You can also
specify a fixed option, which indicates that the pages are permanently fixed
for performance. The fixed option reserves real storage for usage by zFS only
Default value: If metaback_cache_size is specified, then meta_cache_size
is 64 M. If metaback_cache_size is not specified, zFS calculates 10% of real
storage that the system has available during ZFS initialization.
If this amount is less than 64 M, then meta_cache_size is assigned 64 M and
there is no metaback_cache created.
If this amount is between 64 M and 100 M, then meta_cache_size is assigned
10% of real storage size and there is no metaback_cache created.
If this amount is in the range 100 M to 2G+100M, then meta_cache_size is
assigned 100 M and metaback_cache_size is assigned the remainder of the 10% of
real storage size.
If the amount is greater than 2G+100M, then meta_cache_size is assigned
100M and metaback_cache_size is assigned 2 G.
Expected value: A number in the range 1 M - 1024 M. A K or M can be appended to
the value to mean kilobytes or megabytes, respectively.
I had opened an SR with IBM on this same topic. The only guidance I got was to
set these to the minimum and then monitor. Some of these will grow on their
own. Meta_cache_size is confusing. So I just set it to 128M based on what the
Healthchecker was telling me.
So when I did my dynamic change, I got it down, but now it is creeping back up.
And we are not that heavy a use of zFS.
Lizette
> -----Original Message-----
> From: IBM Mainframe Discussion List [mailto:[email protected]]
> On Behalf Of Walter Marguccio
> Sent: Monday, July 06, 2015 7:09 AM
> To: [email protected]
> Subject: zFS high number of real frames
>
> Hello Lizette,all values you mentioned use their default value. I
> have:user_cache_size set to 1229Mvnode_cache_size set to 32768 (I assume
> byte) meta_cache_size set to 100Mmetaback_cache_size set to 1129M Our
> LPAR has 12800M real storage assigned. According to IBM,above default
> values but the 2nd are dependent from the amount of RSin the system .
>
> Walter Marguccio
> z/OS Systems Programmer
> BELENUS LOB Informatic GmbH
> Munich - Germany
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