I use the default 20% value for snapshot reserve. On an F330 our setup looks like this:
10 disks data (35.2 GB) 2 disks snapshots (8.8 GB) 1 disk parity 1 disk hot swap.
Snapshot reserve usage stays about 20% to 50% except when the toaster gets full. As Jim Davis says in his message:
This has been a sticky problem with our F220. We currently use the default schedule in the sysadmin guide, more or less, and that means once you get close to running out of disk space you have a problem -- deleting files just shuffles them from the filesystem to .snapshot, so there's no net savings in disk space. And the .snapshot space will cheerfully spill over the 20% default.
In our case you can delete 8.8GB of data in a 2 week period (we keep 2 weekly snapshots) and see an 8.8GB increase in user free space. If you delete anything beyond 8.8GB you will not see any further increase in user free space. The 8.8GB snapshot reserve has been sufficient for us on toasters where I have restricted the type of data to interactive design databases. The toaster that I allowed simulations on could only run a few hourly and 1 nightly snapshot.
regards, Steve Gremban gremban@ti.com
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On Mon, 31 Mar 1997, Steve Gremban wrote:
I restrict the data going to our toasters to that created interactively by our designers using Cadence. An IC design database may have 6 or more people working in it and if a cell disappears or the database becomes corrupted (for any of a million reasons) we only lose at most a few hours of effort by copying back a previous hourly from snapshots.
We have the following policy: "snap sched 2 6 12", 2 weeklies, 6 nightlys, and 12 hourlies.
what is your snap reserve set at, may i ask?
Tom Yates - Unix Chap - The Mathworks, Inc.
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