I used to adhere to the following discipline. I don't know if this is
useful to you.
Run tarsnap daily. Each archive created is tagged as one of the following:
daily-<filesystem>-YYYYMMDDTHHMMSSZ
weekly-<filesystem>-YYYYMMDDTHHMMSSZ
monthly-<filesystem>-YYYYMMDDTHHMMSSZ
is it the last day of the month? [ "`date -v+1d +%d`" = "1"]
create monthly archive
delete all but the N most recent monthly archives
else is it the last day of the week? [ "`date -v+1d +%u`" = "1"]
create weekly archive
delete all but the M most recent weekly archives
else
create daily archive
delete all but the J most recent daily archives
weekly are taken the last day of the week (Sat or Sun, dep. on your locale)
– monthly are taken on the last day of every month
On Sun, Jun 27, 2021 at 2:12 PM james young <[email protected]> wrote:
> I could be off-base, but I think keeping a lot of extra archives around
> leads to slower archive listing, fsck / cache directory resyncing and
> reconstruction, and restores?
>
> Mac Time Machine backup defaults: 24 hourly, 30 daily, then as many weekly
> backups as space allows.
> My config for tarsnap-cron: 7 daily backups, 5 weekly, 12 monthly.
>
> It's my personal opinion, but a month is a nice buffer. Three days is
> shorter than some holiday weekends, not to mention vacations.
>
> In your place, I'd think about switching to one of the helper scripts
> mentioned in another reply. See if it can work with the archive names as
> they are now. You can copy archives if you want to fit a new archive naming
> scheme ( https://www.tarsnap.com/tips.html#copy-archive ). Or, if you're
> sure you want to stick to the last three days/one month/whatever and YOLO,
> wait that long, verify the backups, then delete archives from the old
> method ( https://www.tarsnap.com/improve-speed.html#faster-delete ).
>
> -James
>
> Sent from my iPad
>
> On Jun 26, 2021, at 3:26 PM, Romo Hu <[email protected]> wrote:
>
> Hi,
>
> My system has a daily cron job that does tarsnap backup which has been
> running since 2017, and "tarsnap --list-archives" shows a lot of archives.
> Should I care? Is it ok to just let the archive number keep growing? If
> there will never be a need to restore data that are more than 3 days old,
> can I just remove all archives that are more than 3 days old? Is it
> possible to configure tarsnap to only keep archives of the recent 3 days?
>
> Regards
> Romu
>
>
--
"Well," Brahmā said, "even after ten thousand explanations, a fool is no
wiser, but an intelligent person requires only two thousand five hundred."
- The Mahābhārata
