[Box Backup] Misc questions about Boxbackup

[Ben Summers]

On 21 Jun 2004, at 14:10, J=E9r=F4me Schell wrote:

> Hi all,
>
> I am currently testing Boxbackup on Linux to see if it is suitable for=20=

> our needs. I have several questions.
>
> I made Debian packages for Boxbackup to simplify the installation,

Any chance you could add those to the Debian collection? Thanks!

>  so I wrote initialisation scripts to start and stop the server and=20
> client daemons.
> I have a little problem with bbackupd. When I try to stop it via my=20
> script (in fact sending a signal 15) while it is in the process of=20
> sending files to the server, it doesn't stop. I see in the log :
> bbackupd[2090]: Exception caught (7/41), reset state and waiting to=20
> retry...
> If I stop it again it really exits but if there are child processes, I=20=

> am afraid of not being able to stop anything without sending the fatal=20=

> SIGKILL :)

I really must fix this one. Now's a good time. It'll be in the next=20
release.

>
> Another thing I am wondering of is if boxbackup preserves ACL. This=20
> could be useful in certain cases but I think ACLs are not very=20
> "standard" accross platform so it should be difficult.

No. I do not support ACLs. I won't be doing so, as I don't have a=20
suitable installation nor the interest -- the platform I need this to=20
run nicely on is OpenBSD.

However, the architecture allows alternative permission schemes, so it=20=

would be easy to add the support without disturbing anything. I would=20
be more than happy to suggest how it should be done and integrate the=20
patch if anyone wants to have a go. All you need do is write one=20
function to write ACL data to a stream and another to read it out and=20
apply it. It really is that simple.

>
> What kind of userland RAID is boxbackup using? Is it RAID 1 or RAID 5.

RAID 5.

> I would say RAID 5 as it needs 3 disks. And, in fact, can it be more=20=

> than 3 disks? (I know it is possible to create more than one disc set,=20=

> but I would like to know why 3 disks :) )

Because I only wrote the code for 3 discs. Supporting more wouldn't be=20=

terribly difficult, but it was easier to write the code with exactly=20
the number in mind. You can get three discs neatly in a 1U server=20
case...

>
> Is it possible to limit the number of revisions of files? I mean=20
> rather than beginning to delete old revisions of files only when the=20=

> storage is full, also begin to delete when the number of revisions for=20=

> the file is reaching a certain number.

I intend to do some work on controlling this more carefully when I do=20
the mark and archive options. So not now, but soon. Next big feature,=20
after I've got the forthcoming maintenance release done.

>
> Would it be possible to have a global daemon running as root and to=20
> allow per-user configuration. For exemple each user would have in his=20=

> home directory a .boxbackup directory that would contain his own=20
> bbackupd.conf (maybe with not all the options of the global one) and=20=

> private key/certificate/encrypt key files. This way we wouldn't have=20=

> to run bbackupquery as root and individual users could backup/restore=20=

> without root intervention. This would probably imply to regularly=20
> launch a child process of bbackupd that would run as the user. This=20
> way the user daemon wouldn't be able to read other user's files ;).=20
> Users would also probably need access to a bbackupd socket to be able=20=

> to use bbackupctl. Do you see any objection that would prevent such=20
> behavior?

I would object to the unnecessary complexity in the daemon. Can I=20
suggest that you run one daemon per user, as that user?

   http://www.fluffy.co.uk/boxbackup/nonroot.html

I think that'll do exactly what you want.

>
> And last (for now) but not least, we need to implement a GUI to add=20
> "user friendly touch" to boxbackup :).

For the moment, I am concentrating on getting the back end systems=20
right and with a good set of features. A GUI is fairly low down on my=20
list of things to do (especially as I would have to learn cross=20
platform GUI stuff), but I will work with anyone who is interested in=20
having a go.

>  I am wondering if we should just encapsulate calls to bbackupquery=20
> and bbackupctl

A good way of doing things.

>  or if there is a way to use the C++ classes as a library that would=20=

> provide transparent access to the boxbackup server (this is just a=20
> thought, I didn't yet look at the code :) ).

Another good way of doing things. (check out test/backupstore for an=20
example of talking to the server directly.)

>
> Sorry, this was a bit long, but I think boxbackup is worth it :)
> And Ben thank you for your great work on boxbackup!
>
Thank you for your support of the project.

Ben