On 16/08/2023 6:17 am, Jon Perryman wrote:
This is absurd. Not all disk is cheap (e.g. GDPS). Not all data is valuable.
While a person may be expensive, not everything they do is of value to the
business and worth the hidden expenses.
It's not cents per GB PC cheap, but it's not 1990s expensive either.
If you have a meeting with a couple of people, schedule a change, get it
approved, implement it... you could easily spend $1000 of people's time,
not to mention add weeks to a project. How much disk space would that
buy you, if you can avoid that cost and delay?
The IBM RDP systems charge $10/month for 5GB of disk space, which seems
expensive. But still, $1000 of meetings avoided will pay for 40GB of
space for a year.
What is the (ballpark) cost per GB on a real customer system? How much
space is it worth to reduce the time spent managing it?
You can't be serious about being a storage admin. Every situation and company
are different. Questions must be asked. How do you not understand adding 100GB
to a filesystem has an impact on GDPS, HSM, backups, recovery and much more. If
you believe, everything is created equal, 100GB has the same impact on a 10GB
or 10TB filesystem. A file system may contain millions of Unix files but its 1
MVS dataset. Recovery of a filesystem is risky at the best of times but add
100GB increases the risks and may impact the nightly archival time (1 Unix file
change causes HSM to backup the entire filesystem). If as you say, data is
valuable, then the UNIX backup would be used. I could go on but I expect this
should be obvious.
Whole filesystem backups are not very useful - really just a DR tool.
What do you do if a user wants file(s) restored? Restore all their files
from a point in time? Or restore the filesystem, mount it somewhere and
manually copy files?
The whole filesystem backup takes us back to the problems with
individual filesystems. You are going to back up a user's whole
filesystem, including all the freespace from the largest file they ever
deleted, because they logged on and updated .sh_history? Or worse - can
the filesystem change indicator tell the difference between a data
update and a metadata (e.g. last accessed date) change?
I'm not saying everything is equal, I'm just saying that freespace is a
lot cheaper than managing a lack of freespace.
--
Andrew Rowley
Black Hill Software
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