Replacing the /home partition by an External File server

[dwhite]

My Desktop machine runs with two Drives an SSD with /, /usr and /var on it but the Swap, /home and /tmp on an older HD. I'm thinking of buying a file server or making it from a Pi, and putting my /home on it. Migrating the desktop /home to it and making it the /home of my ARM tablet the same. I think this would speed up my Desktop or not make it any slower, the devices that access the file and the file sever will all be different OS's but probably just different flavour of Linux. Anyone think of problems or even is this possible.

[doktor5000]

Possible yes. Although I wouldn't bet something on the fact that it would be faster.

Do you have GB ethernet for all participating machines throughout, including switch/router?

[dwhite]

They'd all be part of the same network, my home network, to remove the chance of it being down due to my provider, I got the idea from my all in one WiFi printer its quicker if it's awake. I was thinking of using cat5 network cable, I just don't think wireless is secure. I had a wireless doorbell but I live in a flat and the guy upstairs had the same one, and anyone ringing his door would ring my bell luckily with his tune.

[doktor5000]

You did not answer the question. Doesn't matter if you use cat5, cat6 or cat7 cable.

[dwhite]

What's GB Ethernet?? I am planing on using 10,100 Ethernet because that was what I trained in many years ago. I haven't really kept up though.

[doktor5000]

GB Ethernet is 1000. If you plan on using 100 (called fast ethernet) the maximum gross bandwith is ~12MB/s - IMHO that would not be sufficient for using a network share as a critical local filesystem and makes the network connection clearly a bottleneck. Good luck with that.

FWIW, doesn't matter if you were trained on 10/100, there's no difference to 1000 apart from the speed.

[dwhite]

The cards I've been collecting are 1000Mb/s. an the interfaces in the servers are so I guess I am.

[doktor5000]

And the switch/router where all those are connected to?

[jiml8]

Also, for 1000, the cabling needs to be cat 6.

I personally would not do this; it leaves you vulnerable to more points of failure in your system; if anything in your data path goes down, you lose /home. You will also find your system is much more complicated to boot.

Also, I am not sure an ARM system will be fast enough; you want a connection that is at least as fast as what you would realistically get from a SATA hard drive, and while I have not tried an ARM in such an application, I can tell you that I am able to bury a dual-core Sempron processor in exactly that application...feeding data to/from a NAS to my workstation over a 1 GB ethernet connection. Of course, I am running an encrypted filesystem on my NAS and therefore the processor has to handle encryption/decryption; if you do not encrypt your data, then the workload on the processor will be a lot less. Against that, I am running hardware RAID with a rather high-end RAID controller, and that offloads a lot of work from the CPU. So maybe it is close to a push.

If I was going to do something like what you want to do, I think I would have /home on my hard drive, with the basic configuration files present locally. Then, I would put a mountpoint inside /home and mount my NAS share to that. This would let me put all my private files externally, while still retaining what is needed to keep the system happy if connectivity drops.

[doktor5000]

Also, for 1000, the cabling needs to be cat 6.

Nope, it's not mandatory. cat5 or cat5e can be used for 1000BaseT. The cables are specified for up to 100MHZ, and only 80MHz would be used.

[wintpe]

if you are going to do this, and im only assuming this from the terms used, then dont
mount /home as a hard mount over nfs , use automount.

make an entry in /etc/autofs/auto.master of
/home /etc/autofs/autoto_home.

then in /etc/autofs/auto_home place the following.

fred fileserever:/local/home/fred
joe fileserver:/local/home/joe


etc

install and runup autofs before you start those files.

this then wont effect your bootup, which will not be dependent on your fileservers availability.

keep at least one non root user (admin perhaps) that does not have a home directory in home (or has an override in auto_home
such as
admin :/admin

which will create a loopback for admin so that it looks like its /home/admin, but is really /admin.

automount will only throw the mount when its requested, ie as you login as that user.

so thats the advise for automount

the second bit of advise is, as per jims comment.

a raspberry pie wont cut it, and will make your PC slow to do everything as it will be waiting on io.

instead get something with a bit more go in it.

now im not sure what that is, I personally use a 2 x 4 core socket F opteron, with 20 gig of ram, and 28 TB of mirrored disk, twin bonded
gig ethernet, and some nfs tuning options to make it focus its performance on NFS. the huge amount of ram is for caching the writes.

but it uses about 250 watts, so is expensive to run 24x7.

some of the more recent I5 or I 7 processors may be more power efficient, but will have quite a large outlay.

if its arm you want, there are many quad or 8 core arm boards available now with sata, like Udoo, or beagleboard etc.

take a look at these they will be available soon

http://www.hardkernel.com/main/main.php

the upcoming cubieboard4 also looks promising

as does the Jetsons TK1 (http://www.maplin.co.uk/p/zotac-jetson- ... -kit-a30ny)

also http://www.aliexpress.com/item/Heartsea ... 41737.html cubietruck

they wont perform as well as a amd/intell will, but will be significantly better than a pi.

regards peter

[jiml8]

Not to hijack this thread but...

now im not sure what that is, I personally use a 2 x 4 core socket F opteron, with 20 gig of ram, and 28 TB of mirrored disk, twin bonded
gig ethernet, and some nfs tuning options to make it focus its performance on NFS. the huge amount of ram is for caching the writes.

Do you derive any benefit from the twin ethernet?

My NAS is powered by a dual-core Sempron, 4 GB RAM, and an Areca RAID controller, with 32 TB RAID-6. My workstation is powered by a Phenom-II 955 processor with two 500 GB SSDs and two SATA hard drives and 32 GB RAM. I have observed that my workstation is not able to sustain high speed transfers to-from the SSD; the usual pattern I see for traffic headed between the SSD and the NAS is that data is buffered into memory, then sent on to its destination. If I am writing to the NAS, I'll see a high speed burst from the SSD, followed by a download to the NAS that buries my 1 GB ethernet connection, and also buries my Sempron processor on the NAS. This happens whether I use rsync or cp.

I rarely see what I would prefer to see, which is simultaneous transfers to/from the NAS and from/to the SSD.

I also see the same pattern for transfers among the drives on this workstation.

So, the 1-Gb ethernet connection to my NAS seems to be well matched with the horsepower of my Sempron, the NAS memory seems adequate (seldom fills up), and the NAS performs at a speed slightly greater than the speed I get out of my local SATA drives. However, given that my workstation seems to be unable or unwilling to handle simultaneous transfers, and insists on buffering, I don't see any particular advantage to adding another ethernet interface and increasing processor horsepower.

Hence my question: do you derive benefit from the dual-ethernet connection? If so, how? Of course, your configuration could be very different than mine..

[wintpe]

i use nfs from phenom desktop to server.
the desktop is also bonded, mode 6.
soif im doing two copies simultaniously
then i get the full transfer.
mode 6 bond is a bit like multi thread.

ie single transfers cant take advantage of it.

however then the disks on the nfs server cant keep up,
hence the large memory buffer.

still there are times when it stalls, and i have iowait.

usualy when i try to copy 4 or more parrallel transfers.

we are talking movie files in general of 2 gig or more.

regards peter