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Re: Can MySql database store images?

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Jerry Stuckle wrote:


> It's done every day by a large number of companies.  But your figures
> are way off - on a 10 GB network it would take about 3 hours.

My figures are based on reality with real hosts and other stuff going on on 
both hosts and networks.
 
>>>>> And what happens when you delete a file - but later need to restore it
>>>>> from backup?
>>>>
>>>> You copy it from one of the previous incrementales - specifically the
>>>> one that was triggered due to the file deletion on the source end.
>>>>
>>>
>>> Ah, but you said use rsync - which does not create incrementals.
>>> Rather, it syncs files between two systems.
>>
>> I suggest you top talking now and "man rsync". It does sync filesystems.
>> It also has the option to backup (divert to another directory tree) any
>> file that it is about to delete or update on the target. There are your
>> incrementals. I've been running that method for 10 years - it works.
>>
> 
> OK, now the file gets replaced with a new one of the same name, edited
> and deleted again.  Happens all the time.  Does it still work?

Yes. Of course it does. rsync uses one of two methods to decide to 
replace/update the file on the target:

1) (Cheap) The tuple (pathname,size,mtime) is used as a key - if source and 
target don't match then the target is updated - or more precisely, the 
target is unlinked and a new copy transfered.

This method is sufficient as the only way to break it is by perversly 
updating the mtime of you file to match and older version of the same size.

2) Do the above but include a checksum of the file as part of the tuple.

> And BTW - backups are nice.  But have you ever restored a disk from
> scratch using your method, up to but not including the last 3
> incrementals?
> 
>>>
>>>> You manage how many incrementals you keep by deleting the ones you
>>>> don't want, either consolidating the incremental set to the nearest
>>>> weekly/monthly - or your use the "every incremental looks like a full
>>>> but virtue of hardlinks" and just delete the ones you no longer want.
>>>> Usually in some patter like having the last 7 dailys, 4 weeklys, 12
>>>> monthlys or whatever.
>>>>
>>>
>>> And if you do need to restore the complete disk, you need to restore
>>> from the last full backup plus all incrementals since then.
>>
>> Which bit of "reverse incrementals" are you having difficulty with? The
>> last backup is always a full. You only touch the incrementals if you want
>> an *earlier* copy of the file.
>>
>> Cheers
>>
>> Tim
>>
> 
> And have you ever tried a complete restore to a blank disk of all but
> the last three incrementals?

No because that has never been necessary. A full restore would be required 
for a host failure or a screwup involving massive file deletion.

The incrementals are for users to go picking through when they make a booboo 
on a few of their own files generally.

But in principle, you'd restore the backup then copy on top, in time reverse 
order, the incrementals[1]. 

[1] Ok - this what you will get some surplus files that should not exist, 
but very few people complain of surplus files in the event of disaster 
recovery.

Or if you suspected this would be necessary in your world, and you don;t 
want surplus files, you would use a "cp -rl; rsync" methodology like 
rsnapshop does, that populates the incremental n-1 tree with a set of 
hardlinks to the current tree prior to running rsync. The net result is each 
"incremental" is actually a full snapshot on the day it was run. In which 
case, pick one and restore from it. This method costs inodes on the backup 
filesystem as well as directory overhead of a duplicate set of trees, but is 
not too inefficient for what it does.

Cheers,

Tim

-- 
Tim Watts

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Can MySql database store images? "Robert Crandal" <rcranz143101@gmail.com> - 2011-04-23 23:47 -0700
  Re: Can MySql database store images? "J.O. Aho" <user@example.net> - 2011-04-24 09:23 +0200
    Re: Can MySql database store images? "Robert Crandal" <rcranz143101@gmail.com> - 2011-04-24 01:19 -0700
      Re: Can MySql database store images? "J.O. Aho" <user@example.net> - 2011-04-24 11:13 +0200
  Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-24 11:17 +0100
  Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 13:06 +0100
  Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 08:42 -0400
    Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 14:45 +0100
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 10:27 -0400
        Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 19:04 +0100
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 14:44 -0400
            Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 20:51 +0100
              Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:03 -0400
                Re: Can MySql database store images? Hans Castorp <REWYRLXHEGHO@spammotel.com> - 2011-04-24 23:18 +0200
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 19:55 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:30 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:32 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 12:04 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:18 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:32 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 09:09 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 14:17 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 19:29 -0400
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 12:30 +0100
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:59 +0100
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 18:10 +0100
        Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-24 16:40 -0400
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:05 -0400
            Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-25 02:57 -0400
              Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:59 +0100
                Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-25 21:41 -0400
                Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-26 06:20 -0400
                Re: Can MySql database store images? dougatmilmacdotcom@example.com (Doug Miller) - 2011-04-26 14:10 +0000
                Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-26 22:24 -0400
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-27 08:24 +0100
                Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-27 06:41 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-27 12:32 +0100
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-27 15:07 +0100
                Re: Can MySql database store images? "Peter H. Coffin" <hellsop@ninehells.com> - 2011-04-27 07:11 -0500
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-27 13:34 +0100
                Re: Can MySql database store images? "Peter H. Coffin" <hellsop@ninehells.com> - 2011-04-27 09:25 -0500
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-27 16:32 +0100
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 10:28 -0400
        Re: Can MySql database store images? Norman Peelman <npeelman@cfl.rr.com> - 2011-04-24 16:43 -0400
          Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:36 +0100
            Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:34 -0400
              Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 11:50 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:20 -0400
          Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 12:42 +0100
    Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-24 16:27 +0200
      Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-24 15:38 +0100
        Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-24 16:41 +0200
        Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 19:07 +0100
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 14:46 -0400
            Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-24 21:01 +0100
              Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:10 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:23 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:39 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 12:00 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:27 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:42 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 09:12 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 14:23 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 19:31 -0400
                Re: Can MySql database store images? "Mr. B-o-B" <mr.chew.baka@gmail.com> - 2011-04-25 20:30 -0500
          Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 12:21 +0100
            Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:46 +0100
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 13:23 -0400
        Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-24 20:31 +0200
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 14:48 -0400
            Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-24 21:11 +0200
    Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-24 21:24 +0200
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:34 -0400
        Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-25 12:04 +0200
          Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:40 -0400
            Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 11:48 +0100
              Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:28 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 13:36 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 09:17 -0400
                Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 14:30 +0100
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 18:13 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 19:37 -0400
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 19:35 -0400
    Re: Can MySql database store images? "Robert Crandal" <rcranz143101@gmail.com> - 2011-04-24 13:13 -0700
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:35 -0400
  Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-24 21:29 +0200
    Re: Can MySql database store images? "Robert Crandal" <rcranz143101@gmail.com> - 2011-04-24 14:37 -0700
      Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-25 00:41 +0200
        Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 20:16 -0400
          Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-25 12:12 +0200
            Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 07:31 -0400
        Re: Can MySql database store images? Tim Watts <tw@dionic.net> - 2011-04-25 08:43 +0100
        Re: Can MySql database store images? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-05-01 09:59 +0200
      Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 20:03 -0400
    Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 17:39 -0400
      Re: Can MySql database store images? Axel Schwenke <axel.schwenke@gmx.de> - 2011-04-25 00:46 +0200
        Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-24 20:18 -0400
          Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-25 12:13 +0200
            Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 06:43 -0400
              Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-25 13:40 +0200
                Re: Can MySql database store images? The Natural Philosopher <tnp@invalid.invalid> - 2011-04-25 12:43 +0100
                Re: Can MySql database store images? Jerry Stuckle <jstucklex@attglobal.net> - 2011-04-25 09:19 -0400
                Re: Can MySql database store images? Luuk <Luuk@invalid.lan> - 2011-04-25 16:46 +0200

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