On 07/02/2024 11:07, J. Roeleveld wrote:
Because snapshotting uses so much less space?
So much so that, for normal usage, I probably have no need to delete any
snapshots, for YEARS?
My comment was based on using rsync to copy from the source to the backup
filesystem.
Well, that's EXACTLY what I'm doing too. NO DIFFERENCE. Actually, there
is a minor difference - because I'm using lvm, I'm also using rsync's
"overwrite in place" switch. In other words, it compares source and
destination *in*place*, and if any block has changed, it overwrites the
change, rather than creating a complete new copy.
Because lvm is COW, that means I have two copies of the file, in two
different snapshots, but inasmuch as the files are identical, there's
only one copy of the identical bits.
Okay, space is not an expensive commodity, and you don't want too many
snapshots, simply because digging through all those snapshots would be a
nightmare, but personally I wouldn't use a crude rsync simply because I
prefer to be frugal in my use of resources.
What is "too many"?
I currently have about 1800 snapshots on my server. Do have a tool that
ensures it doesn't get out of hand and will remove several over time.
"Too many" is whatever you define it to be. I'm likely to hang on to my
/home snapshots for yonks. My / snapshots, on the other hand, I delete
anything more than a couple of months old.
If I can store several years of /home snapshots without running out of
space, why shouldn't I? The problem, if I *am* running out of space, I'm
going to have to delete a *lot* of snapshots to make much difference...
Cheers,
Wol
