Re: [ANNOUNCE] Ext3 vs Reiserfs benchmarks

[Matthias Andree]

On Wed, 17 Jul 2002, bill davidsen wrote:

> In article <[e-mail]>,
> Matthias Andree  <[e-mail]> wrote:
> 
> | dsmc fstat()s the file it is currently reading regularly and retries the
> | dump as the changes, and gives up if it is updated too often. Not sure
> | about the server side, and certainly not a useful option for sequential
> | devices that you directly write on. Looks like a cache for the biggest
> | file is necessary.
> 
> Which doesn't address the issue of data in files A, B and C, with
> indices in X and Y. This only works if you flush and freeze all the
> files at one time, making a perfect backup of one at a time results in
> corruption if the database is busy.

Right, but this would have to be taken up with Tivoli "do snapshot as
dsmc starts, backup from snapshot and discard snapshot on exit"

> My favorite example is usenet news on INN, a bunch of circular spools, a
> linear history with two index files, 30-40k overview files, and all of
> it changing with perhaps 3.5MB/sec data and 20-50/sec index writes. Far
> better done with an application backup!

In that case, when you are restoring from backups, you can also
regenerate index files (at least with tradspool, I never looked at the
"News in Dosen" aggregated spools like CNFS or whatever). It's really
hard if you have .dir/.pag style dbm data bases that don't mirror some
other single-file format.