continuous backup solution for freebsd?
Evren Yurtesen
yurtesen at ispro.net.tr
Mon Oct 6 17:07:31 UTC 2008
First of all, I am not an r1soft advocate, but they seem to be making a
software which is popular and affordable and interested in giving
FreeBSD support... r1soft is not the issue here, the problem is that
there is no way to do near continuous backups on FreeBSD servers.
Jeremy Chadwick wrote:
> That said, I'd like to know exactly how "low-level" R1Soft's software
> truly is. dump(8), AFAIK, is "block-level" -- and that's a userland
> program. Does R1Soft's software *truly* require kernel-land? I have
> more to say on that issue (not against R1Soft, but speaking with regards
> to the current state of FreeBSD's developer count) if it truly does.
I think you might not have understood the concept of near continuous
backups. The R1Soft backup monitors the filesystem operations and backs
up written blocks. So it has to know what is written and when to be able
to back it up. The dump command simply reads/writes the blocks. It cant
only read changed blocks. It has to read the whole thing (inefficient).
>> Continuous backups as well as bare-metal-restore seem to be a key
>> feature for many hosters.
>
> Regarding continuous backups: the GEOM gate class could be used for
> this. Meaning, I think it could be used as an alternate to R1Soft's
> software.
The GEOM gate allows mirroring to a remote machine, am I not right? That
would be more or less same as same as using RAID. The continuous backup
(or near continuous) means that you can restore the filesystem to a
point like 15 minutes ago, or 1 hour ago. Besides, I hear geom might
have network delay problems and it is much more complicated setup to
build two machines in mirror configuration just for backup purposes as
well as you cant restore to a point in the past.
> Regarding bare-metal restoration I'm not aware of how to do that under
> FreeBSD, Linux, or even Solaris "with ease". In most cases, companies
> develop their own PXE-booting environments which wipe the disks and
> reinstall + restore data as they see fit. There is no "standard".
OK. Actually there is more than one solution which can do
bare-metal-restores for FreeBSD also. However those solutions at best
rely on nightly backups of the filesystems. With R1Soft, you can restore
the system to only few minutes before the total meltdown.
Unrelated to bare metal restore, with normal backups you are not taking
backups of files which are created/deleted often. For example this can
be customer mails or if a hacker hacks the box and removes his trails.
Even sometimes customers upload some file and remove from their computer
the same they and then accidentally remove from the server. With R1Soft
backup the data would go into the backup server right away and you an
restore every single file independent of when it was put or removed.
>> FreeBSD is loosing users because of this issue.
>
> Why does the "number of FreeBSD users" matter? Quantity does not
> necessarily represent quality.
Thats a perfectly fine statement. But a quality product would be nothing
without users. As well as this problem effects the quality. Consider a
system which has sensitive data which shouldnt get lost, with continuous
data protecton you can restore such failed system to only few minutes
before the failure point. Doing this is currently impossible with
FreeBSD. Best we can do is to return to previous snapshot taken (which
might be a day old). This is an important design criteria since
restoring the lost data might be time consuming and expensive. Thge
issue is not even r1soft, they are just the most popular company giving
such solution, only if there was at least one backup solution which
could provide near continuous data protection...
In addition to this, near continuous backups create less load on boxes
with a lot of reads but little writes. Standart backups have to scan all
the files to detect which files were changed.
> I'm sorry for sounding anti-FreeBSD, but the reality is that people
> should use whatever solutions work best for them -- if that's using
> Windows, Solaris, or Linux, great! Remember that open-source is about
> choice: and choice means supporting the possibility that someone chooses
> something else. Blind one-sided advocacy is very damaging to the
> open-source model and concept.
I agree, and please dont shoot the messenger :) I just have a bunch of
customers who would use FreeBSD but not using only because of this
problem. In addition to that I myself would like to use near continuous
backups as well.
I was just trying to inform the FreeBSD community here so if somebody
can have some time to divert to giving the right advices to r1soft then
we all could benefit from it. It doesnt even have to be free even, with
a reasonable price they can probably hire somebody to work for building
the basics of this feature.
So the real question is, is there anybody who is willing and have the
experience to help on this issue?
Thanks,
Evren
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