Thomas E. Spanjaard wrote:
Stilyan Tsenov wrote:
I can't uderstand whether snapshots are filesystems or files ?...or
just both possible ?
A snapshot of a filesystem needs support from the filesystem to be
snapshottable, e.g. temporary suspension of all activities on that
filesystem while the snapshot-taking is in-progress.
Cheers,
.. except for Plan 9, where the 'snapshot' was basically a byproduct of the way
updates were done - i.e. change (and date) only what HAD changed, preserve all
else - even if no longer 'valid'.
By selecting a date/time, the 'collection' of data current at that time could be
had - ergo instant de fact 'snapshot', and to very fine granularity.
An RDBMS where all records are timestamped and never 'vaccumed' can do much the
same - a device we used for years to 'what if' telco service-mix pricing:
- current, historical, or anticipated telecoms traffic
could be 'billed at'
- current, historical, or anticipated rates.
Made comparison much easier w/r adjusting for this and that..
Bill
