Hello Anna, I believe your snapshot is indeed zero (0) at first. Then as the data changes, your snapshot is holding on to it's read-only blocks. So it makes sense that the snapshot is growing. The more data you turn over, the bigger thw snapshot will be.
A good test: Create a small volume, dump some data into it and then take a snapshot. Examine the snapshot carefully.
Now completely overwrite (delete and then re-write) the data and then look at the same snapshot again.
Theory: your snapshot keeps changing because your 'active filesystem' is changing.
Cheers ......
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-----Original Message----- From: Anna M [mailto:annpurna@gmail.com] Sent: Monday, April 07, 2008 10:18 AM Pacific Standard Time To: toasters@mathworks.com Subject: Re: impact of setting snap reserve to 0
Since I am totally new to the world of filers, I would really appreciate if you can just explain me as to why the snapshot size for a newly created flexclone volume is not zero? After all the source for it also was a snapshot.
The issues in space calculation for a newly clones volume is actually because of the changes in the snapshot size for this vol. For one of my newly cloned flexclone volume I am seeing that with in 3 minutes, the snapshot size reported is altered from /vol/prod_v/ 475777656KB 400203924KB 75573732KB 84% /vol/prod_v/ /vol/prod_v/.snapshot 0KB 74248140KB 0KB ---% /vol/prod_v/.sn
to /vol/prod_v/ 475777656KB 325971708KB 149805948KB 69% /vol/prod_v/ /vol/prod_v/.snapshot 0KB 16112KB 0KB ---% /vol/prod_v/.snapshot
Similarly the agg show_space output that I took at the same time as I took above df command output shows change in allocated and Used space values for this volume as: prod_v 75574680KB 32KB volume . ... prod_v 149823776KB 17816KB volume
O/p for both these commands are still changing... We have found that values take approx 19 minutes to settle down...19 minutes seems to be a BIG duration :-(
Any help in this regard will really be appreciated.
-Anna
bluezman wrote:
Anna M wrote:
snip
Any clue as to why would this be heppening? Can it be because snap reserve is not set properly(we have set it to zero)?
i believe that when you take a clone, it takes a snapshot of the src, since your snapshot space comes out of the actual volume, you will see the size change
correct me if i am wrong.