Re: [Bacula-users] Multiple pools in a single tape?

First of all, thank you Ryan and John for your valuable feedback.

Now, I know that (I think it should be stated clearly in the manuals too - or FAQ, maybe):
- There can only be one spool/volume per media (tape);
- The media can only be recycled in its entirety.

Which leads to:
- There is a need to at least 2 tapes for making recycling possible in a real case.

Unfortunatelly, this is bad news to me, as I will comment along the message below...

Ryan Novosielski escreveu:

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Rodrigo Rosenfeld Rosas wrote:

Hi, I'm new to bacula and trying to set it up for our environment.

We are a small office with not too data to backup. I mean, a single 200 
GB tape would do the job perfectly, as today.

A single 200 GB tape is never a perfect backup. You really should have a
minimum of 3 tapes in most situations. In your case, it sounds like 6.
Consider the tape can fail while writing to it. You may lose your only
backup while this is happening. The tape could fail on the shelf as
well, even if you have two tapes... you are therefore vulnerable while
the tape is being written to, if some reason the tape on the shelf
should not be readable. I realize one can plan this out ad-nauseum, but
I think that 3 is a good balance. You may not need 600 GB, so if you can
get smaller tapes, that works, but considering especially that you
cannot recycle part of a volume, I don't think 1 tape is a good idea.

I agree with you, but there are other considerations. I wonder how good would be if backup was the only concern of my job. Actually, I would prefer my company to hire at least a backup specialist to worry exclusively about backup, considering its importance. But unfortunatelly, backup tasks are similar to goal keepers. People usually only admire their work in the penalties time or when they do something wrong... People only worry about backup when a disaster occur. When we are working on improving or implementing backup solutions, it seems where are doing nothing for most people. This is a major problem when we have other demands, which is my case.

Besides backup, I am responsible for:
- programming two complex web systems with constant improvements requirements;
- help desk support;
- system administration (network infrastructure, ActiveDirectory, integrating Linux clients in a Windows networking, etc);
- proxy, gateway, firewall/security, anti-virus, system update;
- maintaining a remote server in collocation service (apache/ruby on rails/log rotation/backup/database/firewall/etc)
- simple gif creations and all computer related stuff my company needs, as I am the only computer specialist here...

Fortunatelly I am not responsible for implementing the mail server :)

Not that I am complaing about that (I've already complained to the right person, but he didn't hire anyone else yet). Actually, I like learning new things, but the problem is that I'm not that good to reach the expectations about what I am supposed to do in the desired deadlines.

All this story is to say that I know I won't implement the perfect backup solution. Mainly because if I think too much in the backup solution, it seems to others that I am not doing my work, since nobody cares to backup until there is a disaster, which, fortunatelly, didn't happen yet since I'm working here (a year and a half past). But at the same time, I don't want to think what would happen if some important data was lost due to a backup system failure... When this happen, they will remember I'm responsible for backup too.

Now, let me explain why it is bad news not beeing able to reclycle the tape partially:

First of all, we don't have a changer. This means I would need to change the tapes every day, manually, assuming I will be here all days from monday to friday.

Secondly, the e-mail folder is just an example about different recycling period for different folders. I have other folders with different recycling period issues. This would demand me several tapes and to change them several times. Even worse, I would like all backups to occur at night, when there is no one working in the files and even if I was willing to wait the backup to finish for changing the tapes at night, I couldn't do it anyway because the building would be closed at this time.

So, now that I realized that I over estimated Bacula's features, I still need to think about a solution to my problem and if you are kind enough, you could give me a hint or an insight I didn't get yet. If just Bacula supported differential files backup (in the diff sense), I could backup the e-mails in the same way I backup the other files and this would help a lot (although I'm not very sure about this)...

Currently I use Windows Backup utility to backup to the same disk as a temporary solution with 2 months file retention. But it is a very bad software and Bacula would do the job much better, but I would like to use the tapes instead of the disk. We actually have about 3 tapes (but I could ask more if it is necessary).

Once more I'd like to thank you both a lot for the valuable information for taking your precious time and to sorry about the long message.

Best Regards,

Rodrigo.

But I have a problem and couldn't find the solution reading Bacula's 
manuals.

There is a folder I need to backup containing mbox files, among other 
folders. I need to retain the mail folder (about 5GB currently) for two 
days only, one full backup per day, while I need to retain the other 
folders for about 5 months.

Reading the manuals, I found out that setting the file retention or job 
retetion doesn't delete the files on media, as I wanted.

Nothing will. The whole media is recycled at once, so everything on the
tape will need to be erased at the same time.

So it seems to me that if I wanted the desired result, I would need to 
define 2 pools using the same tape, so that I can configure different 
Volume Retentions.

It would be best in this case, yeah.

Is that right? It doesn't seem logic to me, as a pool is supposed to 
support multiple volumes or tapes and this configuration would give me a 
tape containing 2 pools...

Pools are just pools of storage. You'd have your tapes for mail, and
your tapes for the other files. You could then use those tapes for a
rotation within those pools.

Please, tell me what would be the better approach to my problem...

You've almost got it, but you cannot use the same tape. I think that is
what is confusing you.

- --
 ---- _  _ _  _ ___  _  _  _
 |Y#| |  | |\/| |  \ |\ |  | |Ryan Novosielski - Systems Programmer II
 |$&| |__| |  | |__/ | \| _| |novosirj AT umdnj DOT edu - 973/972.0922 (2-0922)
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