Len Boyle writes:
> Does anyone have an estimate for the average space used for the
> catalog space for each object. I believe someone reported 600 bytes
> per file. But this seems high for an average when the objects are
> compressed.
>
> For 1 million files x 600 bytes x 2 for duplexing x 10 for
> 10 generations or cycles this is 1.2 x 10 to the 10th power.
I think I was the one who reported the number for WDSF. It comes from the
WDSF Administrator's Guide, p 15:
Database space(in 3380 equivalent cylinders) = Total files/1050(files/cyl)
At 600k per cylinder, this comes to 585 bytes/file.
As Len points out, the ADSM documentation doesn't provide similar planning
rules of thumb (This is a significant omission, I believe). We aren't running
ADSM in production yet and have just run some preliminary server tests.
These early results, for a two clients (one MS Windows, one AIX) indicate
the following:
# of files = 38,000 (from q occ)
# of used database pages = 7600 = (at 4k bytes/page) 30M bytes
bytes/file = 30M/38000 = 830
This estimate may be a bit high as the q occ command (see one of my previous
appends) only reports the # of files, not the total # of objects. Even giving
them the benefit of the doubt, the estimate of 600 bytes/file is still
the right order of magnitude.
Hence, the computation appears about right. For a million files, 10 generations,
2 copies, you need about 10 gigabytes for the database.
Regards, MK
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