Forgot your password?
typodupeerror

+ - Ask Slashdot: Replicated filesystem for linux - disconnected use

Submitted by TarpaKungs
TarpaKungs (466496) writes "There are many clustered filesystems for linux — most seem to have HPC clustering or failover in mind and assume there is relatively continuous network connectivity between the hosts.

I'm after one that would suit multiple clients (laptops typically) in a "business/home" usage scenario with very intermittent connectivity.

Right now, I have a central fileserver at home which is backed up properly and similar at work. I work mostly on a laptop (which is the way everyone in my family and most of my work colleagues are going. I occasionally sync back to my home server and work servers with unison over ssh, which is a great tool.

I'm not looking for a caching solution that depends on the network being there — I'm after a full on replicated (at the file level, not the block) filesystem preferably with no concept of a master (unison handles this quite well).

So there seem to be a couple of directions I could take:

1) Run unison as root from a script with a carefully chosen config file per FS area. Write a script runs when (say) at-home WiFi is detected, so as to avoid syncing over a mobile link. Email errors to me for manual fixing (unison generally "does the right thing" and baulks before doing something that is not provably correct).

Or

2) Find a more elegant solution that works at the kernel or daemon level.

So:

1 — Anyone done this and did it work out?

2 — Are there any well maintained linux network filesystems worth looking at that would behave well in a WAN-with-intermittent-connectivity context?

Cheers

Tim"

Comment: Re:Passwords (Score 1) 144

by TarpaKungs (#43355901) Attached to: MIT To End Open-Network Policy In Response To Recent Attacks

IME most kerberos servers store the database key in what they term a "stash file". That's current practise too.

Unless you need the level of security that you have to go upto the console and present a key when the system reboots or the KDC service restarts, there isn't any other way. Essentially, for most real world systems, the kerberos primary and slaves need to be regarded as machines to be kept highly secure or it's game over.

Is AD any different?

Comment: Re:Just the tanks? (Score 1) 114

by TarpaKungs (#42103861) Attached to: Datagram Recovers From 'Apocalyptic' Flooding During Sandy

You mean like garage forecourt (petrol station) tanks that are invariably underground?

Those are usually a sealed tank with filling and vent pipes above ground. Now, as the filling pipes are capped when not in use, only the vent pipes would be at risk from flooding - and those can be taken up as many storeys as required and vented to the open air (away from windows and aircon intakes obviously).

The pumps could be located above the flood zone feeding generators also above the floodzone.

Comment: Re:Maybe they like it that way? (Score 1) 138

by TarpaKungs (#41093407) Attached to: Ask Slashdot: Best VPN Service For Australia?

Don't you think it's more likely that requiring plumbing be done by expensive card carrying professionals will actually cause more leaks not to be fixed as the householder will now have to pay, what, $50-$100 for a plumber to come and fix that dripping tap or overflowing toilet cistern vs a few dollars in parts to do it themselves?

Besides, how many DIY plumbers would actually leave a leaking joint in place?

Comment: Re:Maybe they like it that way? (Score 1) 138

by TarpaKungs (#41093053) Attached to: Ask Slashdot: Best VPN Service For Australia?

Knowing about how Australia likes to regulate home electrical work and even plumbing (I'm talking water, not gas here) I would say the average Australian is either very much asleep or very much likes being cared for by Nanny.

Not quite what I would expect from the children of pioneering emigrants looking to forge a new life...

I rest my case...

Comment: Re:Maybe they like it that way? (Score 1) 138

by TarpaKungs (#41092385) Attached to: Ask Slashdot: Best VPN Service For Australia?

Do you mean you have no problem with there being "regulations" (eg IEE/IET wiring regs for the UK, NEC for the USA, VDE etc)?

Or are you saying you approve of running plumbing and wiring as a closed shop, artisan style?

The former is necessary - but I have not problems making my wiring IEE 17th compliant. OTOH I detest closed shop practices and I'm surprised and slightly disappointed the Australians put up with it.

In which case I can see how they might like Nanny watching "the Internet" to keep the bad men away...

Comment: Re:Maybe they like it that way? (Score 1) 138

by TarpaKungs (#41092127) Attached to: Ask Slashdot: Best VPN Service For Australia?

I do not think DIY should be regulated beyond requiring that the person doing the work "is competent" (which is what the laws pertaining to UK gas plumbing state[1])

England and Wales went through this in 2005 with the introduction of "Part P" of the Building Regulations. Basically anyone doing electrical work that is notifiable (most major work) must either be registered or must report the work to the Building Control dept of the local council for a fee. The councils generally don;t know how to handle this so mostly just get an electrician in afterwards to perform a full system test for another fee making, say adding a new circuit cost around £200-300 in fees alone.

Prior to the introduction of Part P the government's own stats for England and Wales stated there were around 5 deaths per year from fixed electrical wiring. It notes a further 25 possible deaths due to fires where the fire was due to an electrical source of ignition but that does not break down into fixed wiring vs appliances and extension leads. Most informed sources estimate the number of deaths from fixed wiring directly or by resulting fire to be around 10 per year.

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CFsQFjAA&url=http%3A%2F%2Fwww.stockport.gov.uk%2F2013%2F2994%2Fdevelopmentcontrol%2F14406%2F41351%2Fpartpelectricalsafety&ei=QvU1UJaYHe210QW8mIDoBQ&usg=AFQjCNGZgEjqrIWPIGTCIWqii5Metf20jw&sig2=2aV0bfyQw0v8RUIUotcsTg

The number of deaths on the road in the GB was 1901 in 2011. Scale that back a bit to remove Scotland.

Do I think limiting who can do electrical work is a waste of resources? Yes I do. The resources would be far better spend on road safety.

To require being a member of an accredited institution to do water plumbing (with the possible exception of sealed heating systems) is even more laughable.

There is a difference between regulation and limiting electrical and plumbing work to members of a closed shop artisan/union style which seems to be the case in Australia and becoming the case in the UK.

[1] I am legally allowed to do my own gas work in England, provided it is "not for hire or reward".

Comment: Maybe they like it that way? (Score 0) 138

by TarpaKungs (#41092003) Attached to: Ask Slashdot: Best VPN Service For Australia?

Knowing about how Australia likes to regulate home electrical work and even plumbing (I'm talking water, not gas here) I would say the average Australian is either very much asleep or very much likes being cared for by Nanny.

Not quite what I would expect from the children of pioneering emigrants looking to force a new life...

Comment: Re:Unfortunately, UK has become Uncle Sam's lapdog (Score 1) 1065

Not going to happen.

We have two main parties who are now extremely similar in politics and a third "half" who lacks spine and a mismash of tiny parties who will never get represenation under our current voting system.

Coupled with the fact that the majority of the people are either apathetic (because they believe the above is insoluble) or just uninformed (and do not care to be), there is absolutely no chance of anything changing in this country. We've been this way for decades now - the last major movement of consequence was the Suffragettes.

If I have seen farther than others, it is because I was standing on the shoulders of giants. -- Isaac Newton

Working...