Re: [gentoo-user] Using date/time variables in cronjobs?

[Volker Armin Hemmann <volkerarmin@googlemail.com>]

Am 06.05.2013 01:21, schrieb Tanstaafl:
> Last question...
>
> In order to keep only a certain number of backups, what would be the
> easiest and SAFEST way to delete the older ones?
>
> For example, I want to keep 17 hourlies, and 30 nightlies, so I have
> two cron jobs set up, the hourly, and the nightly. Each backs up to a
> separate dir.
>
> I'm thinking the easiest way would be to find and delete the oldest
> file in the backup target directory before executing the backup command.
>
> For the hourlies dir, I'd just find the files that are older than one
> day - so maybe:
>
> find $BACKUP_DIR/hourly* -type f -mtime +1 -delete
>
> Would that do it?
>
> So, in my script, I could add this in like:
>
> #!/bin/bash
> BACKUP_DIR="/home/user/mypg_backups/hourly"
> PGUSER="superuser"
> PGyy=`date '+%Y'`
> PGmm=`date '+%m'`
> PGdd=`date '+%d_'`
> PGtt=`date '+%H:%M'`
> find $BACKUP_DIR* -type f -mtime +1 -delete
> /usr/bin/pg_dumpall -U $PGUSER -o -f
> $BACKUP_DIR/mypg-$PGyy-$PGmm-$PGdd$PGtt.gz
>
> and for the nightly backup script, since I want to keep 30 days worth:
>
> #!/bin/bash
> BACKUP_DIR="/home/user/mypg_backups/nightly"
> PGUSER="superuser"
> PGyy=`date '+%Y'`
> PGmm=`date '+%m'`
> PGdd=`date '+%d_'`
> PGtt=`date '+%H:%M'`
> find $BACKUP_DIR* -type f -mtime +30 -delete
> /usr/bin/pg_dumpall -U $PGUSER -o -f
> $BACKUP_DIR/mypg-$PGyy-$PGmm-$PGdd$PGtt.gz
>
> Am I asking for trouble doing it this way?
>
> On 2013-05-05 5:56 PM, Tanstaafl <tanstaafl@libertytrek.org> wrote:
>> So, my final script looks like this:
>>
>> #!/bin/bash
>> BACKUP_DIR="/home/user/mypg_backups"
>> PGUSER="superuser"
>> PGyy=`date '+%Y'`
>> PGmm=`date '+%m'`
>> PGdd=`date '+%d_'`
>> PGtt=`date '+%H:%M'`
>> /usr/bin/pg_dumpall -U $PGUSER -o -f
>> $BACKUP_DIR/mypg-$PGyy-$PGmm-$PGdd$PGtt.gz
>>
>> For some reason, if I put the underscore in the filename itself, ie:
>>
>> $BACKUP_DIR/mypg-$PGyy-$PGmm-$PGdd_$PGtt.gz
>>
>> It omitted the $PGdd variable entirely.
>>
>> I had to add the underscore into the variable to get the output like I
>> wanted. Weird...
>>
>> Anyway, this is working perfectly, thanks guys.
>>
>
>
>
and then your backup scripts fails without you noticing and you just
removed all your backups. oops.