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Old 01-09-2011, 03:41 PM
David Groos
 
Default LTSP over wireless?

My research tells me that LTSP hasn't been officially supported over wireless connections, but that it's possible if you put a minimum kernel on a flash drive, and initiate the boot from there, though this then isn't really an LTSP system.* I see some comments on forums and list-archives but many are from years ago.



Since I don't know all of the technological underpinnings of all of the involved systems, I'm asking those of you who do know these technologies (or enough to weigh in): have wireless boot possibilities changed with the advances of wireless and networking and hardware and Ubuntu?* Is wireless thin/localapp/fat client/drbl on the horizon?* This is important to know as it opens up many options.


Thanks,
David

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Old 01-09-2011, 03:41 PM
David Groos
 
Default LTSP over wireless?

My research tells me that LTSP hasn't been officially supported over wireless connections, but that it's possible if you put a minimum kernel on a flash drive, and initiate the boot from there, though this then isn't really an LTSP system.* I see some comments on forums and list-archives but many are from years ago.



Since I don't know all of the technological underpinnings of all of the involved systems, I'm asking those of you who do know these technologies (or enough to weigh in): have wireless boot possibilities changed with the advances of wireless and networking and hardware and Ubuntu?* Is wireless thin/localapp/fat client/drbl on the horizon?* This is important to know as it opens up many options.


Thanks,
David

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Old 01-09-2011, 03:41 PM
David Groos
 
Default LTSP over wireless?

My research tells me that LTSP hasn't been officially supported over wireless connections, but that it's possible if you put a minimum kernel on a flash drive, and initiate the boot from there, though this then isn't really an LTSP system.* I see some comments on forums and list-archives but many are from years ago.



Since I don't know all of the technological underpinnings of all of the involved systems, I'm asking those of you who do know these technologies (or enough to weigh in): have wireless boot possibilities changed with the advances of wireless and networking and hardware and Ubuntu?* Is wireless thin/localapp/fat client/drbl on the horizon?* This is important to know as it opens up many options.


Thanks,
David

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Old 01-09-2011, 10:41 PM
David Groos
 
Default LTSP over wireless?

Hi All,
Here's an update on this topic from the discussion on the edubuntu channel today.* I edited it a bit for brevity and focus and ease of reading.* This will be useful to document the ideas given.
David



alkisg: LTSP over wireless will be kinda slow, maybe *nx would fare better

dgroos: Possible, though?* How about with gigabit wireless with a ratio of 1 router to 10 clients?

alkisg: Sure, it's possible, as long as you have an appropriate initramfs locally, e.g. in a usb stick

To check if the performance suffices, you can temporarily test with XDMCP, it has the same performance as ltsp
I.e. enable xdmcp in /etc/gdm/custom.conf, and run X -query on e.g. 10 standalone clients over wireless

I've never seen a gigabit wireless link so I don't know how that would perform

vmlintu:* fat clients might perform better over wireless

dgroos:* Right, wireless N is rated at 300 MB/sec...
Thanks for the ideas to try the XDMCP, I'll give that a go in the coming month or 2 and get back to the list.

thanks for the idea--I would just need an additional 512 MB ram for each thin client I'm on and they should work fine (Pentinum 4's).

vmlintu:* I should do some testing with fat clients over wireless some day too


alkisg:* Some form of local image cloning + syncing is needed there, otherwise with regular 50mbps wireless they're slow
I read a paper once about a modified nfs client that used lots of local caching, that would be ideal but I don't think they're maintaining it after the initial implementatino


mhall119:* IIRC, samba does a good job of local caching

alkisg:* mhall119: that persists across reboots?

mhall119:* probably not, no

alkisg:* That wouldn't help then

dgroos:* when you say 'local image cloning + syncing' do you mean that the disk image would be stored on the USB flash drive, and that that image would be synched during each session?


alkisg: yes, but ideally it wouldn't need to be synced as a whole, but only the parts that the clients needs to read each time
So it wouldn't add any boot or other overhead
E.g. the user would say "reserve 1 Gb on that usb stick for caching", and that'd be all, even if the fat client image was 10 Gb.


dgroos:* So, this is LTSP with a fat client but 'X' is stored locally on a USB stick, with the parts of X updated as needed.* Not quite sure what this, "X" is, yet.* Are you saying that the USB stick would have 10 GB on it or 1 GB?


alkisg:* 1
dgroos:* ... So, the incrementally updated image might be about 1 gig only.* This 'cached' info, that's on RAM?* Thus the need for more than 2 GB RAM?* Or that could be on the USB stick?


alkisg:* No no it's not related to RAM, I just tried to give a similar example
*The clients wouldn't need any additional RAM for that, the cache would be on the usb stick, stored asynchronously so that it wouldn't add any overhead

*E.g. when you have an 1 Gb image, and a client boots, it might read just 20-50 Mb
It would store those on the stick, so the next time it booted it would just have to ask the server "has this part changed? no? then I'll read it from the stick, don't send it to me over the network"


dgroos:* Right.* And stick access is pretty quick!
How much work/time do you see setting up something like this would take someone in-the-know?

alkisg:* And scales well. And local disks could also be used (e.g. ntfs partitions), if available

*A lot, implementing properly a caching file system over the network is no easy task. E.g. that caching nfs-client was implemented but abandoned, I'm sure there's a reason behind it abandonment

dgroos:* I wonder how important this feature would be to other educators?


alkisg:* A lot, it'd be useful for 100mbps networks too, and if implemented properly (with caching ldap) it would even allow a classroom to be still used when a server goes down
(not exactly ltsp anymore...)


dgroos:* It seems there would be *lots* of overlap, however.

alkisg:* I think in Spain they chose to sync the image from the server on each boot instead of using ltsp, I imagine if such a thing was implemented they would use it too (thousands of installations there)


dgroos:* There site is powered by plone... http://www.guadalinex.org/que-es-guadalinex

vmlintu:* Maybe the ltsp image could be sync'ed in initramfs to local hard drive

That might be worth a try.. it'd take quite a long time to transfer a 10 gig fat client image, though..

dgroos:* How often would this have to happen?

vmlintu:* every time the image changes, I guess
Using rsync would probably shorten the time quite a bit, though


dgroos:* could it be only the part that had changed--incremental I'm trying to say, somehow?

vmlintu:* rsync transfers only the parts that have changed - we use that now to transfer ltsp images to our servers


dgroos:* OK.* Could one use USB sticks instead of HD to increase speed, significantly?

vmlintu:* most usb sticks I have tried have been slower than hard drives

alkisg:* dgroos: are you mainly talking about thin or fat clients?


alkisg:* Because if you have enough bandwidth for thin clients (sending videos, X traffic etc) it would more than cover the networked-disk part... not much need for caching there

dgroos:* Well, I'm very big into recycling older Pentium 3 and 4 machines so I would say for the near future thin clients using lots of localapps, but if it were just pentium 4's with a gig of RAM I'd say fat clients for sure.


alkisg:* dgroos: nice, but as in the local ministry proposal, I'd prefer a little larger tables, with an ltsp server on the bottom of each table
This way the netbooks/pcs/tablets/whatever there could have wired connections to the ltsp server, and the server be wirelessly connected to the internet


dgroos:* Excellent idea with the local ltsp server!
*I could make that work, maybe...
Would a pentium 4 with 1 gig ram be enough for a 3-computer ltsp server?* Would sch-scripts still work on them?
would it need a gig NIC?


alkisg:* That server could have 3x100mbps network cards, I think that'd be cheaper than gigabit+switch+whatever
*sch-scripts would work, sure
About the pentium 4 with 1 gb ram... well it would work, but I don't know if you'd be satisfied with the performance


dgroos:* How about the performance if the other 3 were running as fat clients?* as localapps? if the server had 2 gigs ram?* I know you don't know from experience--just asking your best guess.

alkisg:* For fat clients, you can have a very old ltsp server with just 512 MB RAM and a fast disk

No cpu/much ram is needed there
Of course if you have 2 Gb, it'll be used for caching...

dgroos:* regular 7200 fast *enough*?

alkisg:* Sure

dgroos
:* I'll be doing tests on this in the next couple of months and report back

dgroos: I'll post related parts of this to my question on the list serve as well.

alkisg:* dgroos: have you ever checked multiseat?
It allows a single pc to have lots of screens + mice + keyboards
Check the video there: http://www2.userful.com/products/userful-multiseat-linux

There are multiple implementations, I just gave the link for the nice video

dgroos: Thanks!* I'll be checking that out as well, and adding some notes to my blog...
[4:58PM] dgroos: Thanks alkisg, vmlintu and mhall119!

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Old 01-09-2011, 10:41 PM
David Groos
 
Default LTSP over wireless?

Hi All,
Here's an update on this topic from the discussion on the edubuntu channel today.* I edited it a bit for brevity and focus and ease of reading.* This will be useful to document the ideas given.
David



alkisg: LTSP over wireless will be kinda slow, maybe *nx would fare better

dgroos: Possible, though?* How about with gigabit wireless with a ratio of 1 router to 10 clients?

alkisg: Sure, it's possible, as long as you have an appropriate initramfs locally, e.g. in a usb stick

To check if the performance suffices, you can temporarily test with XDMCP, it has the same performance as ltsp
I.e. enable xdmcp in /etc/gdm/custom.conf, and run X -query on e.g. 10 standalone clients over wireless

I've never seen a gigabit wireless link so I don't know how that would perform

vmlintu:* fat clients might perform better over wireless

dgroos:* Right, wireless N is rated at 300 MB/sec...
Thanks for the ideas to try the XDMCP, I'll give that a go in the coming month or 2 and get back to the list.

thanks for the idea--I would just need an additional 512 MB ram for each thin client I'm on and they should work fine (Pentinum 4's).

vmlintu:* I should do some testing with fat clients over wireless some day too


alkisg:* Some form of local image cloning + syncing is needed there, otherwise with regular 50mbps wireless they're slow
I read a paper once about a modified nfs client that used lots of local caching, that would be ideal but I don't think they're maintaining it after the initial implementatino


mhall119:* IIRC, samba does a good job of local caching

alkisg:* mhall119: that persists across reboots?

mhall119:* probably not, no

alkisg:* That wouldn't help then

dgroos:* when you say 'local image cloning + syncing' do you mean that the disk image would be stored on the USB flash drive, and that that image would be synched during each session?


alkisg: yes, but ideally it wouldn't need to be synced as a whole, but only the parts that the clients needs to read each time
So it wouldn't add any boot or other overhead
E.g. the user would say "reserve 1 Gb on that usb stick for caching", and that'd be all, even if the fat client image was 10 Gb.


dgroos:* So, this is LTSP with a fat client but 'X' is stored locally on a USB stick, with the parts of X updated as needed.* Not quite sure what this, "X" is, yet.* Are you saying that the USB stick would have 10 GB on it or 1 GB?


alkisg:* 1
dgroos:* ... So, the incrementally updated image might be about 1 gig only.* This 'cached' info, that's on RAM?* Thus the need for more than 2 GB RAM?* Or that could be on the USB stick?


alkisg:* No no it's not related to RAM, I just tried to give a similar example
*The clients wouldn't need any additional RAM for that, the cache would be on the usb stick, stored asynchronously so that it wouldn't add any overhead

*E.g. when you have an 1 Gb image, and a client boots, it might read just 20-50 Mb
It would store those on the stick, so the next time it booted it would just have to ask the server "has this part changed? no? then I'll read it from the stick, don't send it to me over the network"


dgroos:* Right.* And stick access is pretty quick!
How much work/time do you see setting up something like this would take someone in-the-know?

alkisg:* And scales well. And local disks could also be used (e.g. ntfs partitions), if available

*A lot, implementing properly a caching file system over the network is no easy task. E.g. that caching nfs-client was implemented but abandoned, I'm sure there's a reason behind it abandonment

dgroos:* I wonder how important this feature would be to other educators?


alkisg:* A lot, it'd be useful for 100mbps networks too, and if implemented properly (with caching ldap) it would even allow a classroom to be still used when a server goes down
(not exactly ltsp anymore...)


dgroos:* It seems there would be *lots* of overlap, however.

alkisg:* I think in Spain they chose to sync the image from the server on each boot instead of using ltsp, I imagine if such a thing was implemented they would use it too (thousands of installations there)


dgroos:* There site is powered by plone... http://www.guadalinex.org/que-es-guadalinex

vmlintu:* Maybe the ltsp image could be sync'ed in initramfs to local hard drive

That might be worth a try.. it'd take quite a long time to transfer a 10 gig fat client image, though..

dgroos:* How often would this have to happen?

vmlintu:* every time the image changes, I guess
Using rsync would probably shorten the time quite a bit, though


dgroos:* could it be only the part that had changed--incremental I'm trying to say, somehow?

vmlintu:* rsync transfers only the parts that have changed - we use that now to transfer ltsp images to our servers


dgroos:* OK.* Could one use USB sticks instead of HD to increase speed, significantly?

vmlintu:* most usb sticks I have tried have been slower than hard drives

alkisg:* dgroos: are you mainly talking about thin or fat clients?


alkisg:* Because if you have enough bandwidth for thin clients (sending videos, X traffic etc) it would more than cover the networked-disk part... not much need for caching there

dgroos:* Well, I'm very big into recycling older Pentium 3 and 4 machines so I would say for the near future thin clients using lots of localapps, but if it were just pentium 4's with a gig of RAM I'd say fat clients for sure.


alkisg:* dgroos: nice, but as in the local ministry proposal, I'd prefer a little larger tables, with an ltsp server on the bottom of each table
This way the netbooks/pcs/tablets/whatever there could have wired connections to the ltsp server, and the server be wirelessly connected to the internet


dgroos:* Excellent idea with the local ltsp server!
*I could make that work, maybe...
Would a pentium 4 with 1 gig ram be enough for a 3-computer ltsp server?* Would sch-scripts still work on them?
would it need a gig NIC?


alkisg:* That server could have 3x100mbps network cards, I think that'd be cheaper than gigabit+switch+whatever
*sch-scripts would work, sure
About the pentium 4 with 1 gb ram... well it would work, but I don't know if you'd be satisfied with the performance


dgroos:* How about the performance if the other 3 were running as fat clients?* as localapps? if the server had 2 gigs ram?* I know you don't know from experience--just asking your best guess.

alkisg:* For fat clients, you can have a very old ltsp server with just 512 MB RAM and a fast disk

No cpu/much ram is needed there
Of course if you have 2 Gb, it'll be used for caching...

dgroos:* regular 7200 fast *enough*?

alkisg:* Sure

dgroos
:* I'll be doing tests on this in the next couple of months and report back

dgroos: I'll post related parts of this to my question on the list serve as well.

alkisg:* dgroos: have you ever checked multiseat?
It allows a single pc to have lots of screens + mice + keyboards
Check the video there: http://www2.userful.com/products/userful-multiseat-linux

There are multiple implementations, I just gave the link for the nice video

dgroos: Thanks!* I'll be checking that out as well, and adding some notes to my blog...
[4:58PM] dgroos: Thanks alkisg, vmlintu and mhall119!

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Old 01-09-2011, 10:41 PM
David Groos
 
Default LTSP over wireless?

Hi All,
Here's an update on this topic from the discussion on the edubuntu channel today.* I edited it a bit for brevity and focus and ease of reading.* This will be useful to document the ideas given.
David



alkisg: LTSP over wireless will be kinda slow, maybe *nx would fare better

dgroos: Possible, though?* How about with gigabit wireless with a ratio of 1 router to 10 clients?

alkisg: Sure, it's possible, as long as you have an appropriate initramfs locally, e.g. in a usb stick

To check if the performance suffices, you can temporarily test with XDMCP, it has the same performance as ltsp
I.e. enable xdmcp in /etc/gdm/custom.conf, and run X -query on e.g. 10 standalone clients over wireless

I've never seen a gigabit wireless link so I don't know how that would perform

vmlintu:* fat clients might perform better over wireless

dgroos:* Right, wireless N is rated at 300 MB/sec...
Thanks for the ideas to try the XDMCP, I'll give that a go in the coming month or 2 and get back to the list.

thanks for the idea--I would just need an additional 512 MB ram for each thin client I'm on and they should work fine (Pentinum 4's).

vmlintu:* I should do some testing with fat clients over wireless some day too


alkisg:* Some form of local image cloning + syncing is needed there, otherwise with regular 50mbps wireless they're slow
I read a paper once about a modified nfs client that used lots of local caching, that would be ideal but I don't think they're maintaining it after the initial implementatino


mhall119:* IIRC, samba does a good job of local caching

alkisg:* mhall119: that persists across reboots?

mhall119:* probably not, no

alkisg:* That wouldn't help then

dgroos:* when you say 'local image cloning + syncing' do you mean that the disk image would be stored on the USB flash drive, and that that image would be synched during each session?


alkisg: yes, but ideally it wouldn't need to be synced as a whole, but only the parts that the clients needs to read each time
So it wouldn't add any boot or other overhead
E.g. the user would say "reserve 1 Gb on that usb stick for caching", and that'd be all, even if the fat client image was 10 Gb.


dgroos:* So, this is LTSP with a fat client but 'X' is stored locally on a USB stick, with the parts of X updated as needed.* Not quite sure what this, "X" is, yet.* Are you saying that the USB stick would have 10 GB on it or 1 GB?


alkisg:* 1
dgroos:* ... So, the incrementally updated image might be about 1 gig only.* This 'cached' info, that's on RAM?* Thus the need for more than 2 GB RAM?* Or that could be on the USB stick?


alkisg:* No no it's not related to RAM, I just tried to give a similar example
*The clients wouldn't need any additional RAM for that, the cache would be on the usb stick, stored asynchronously so that it wouldn't add any overhead

*E.g. when you have an 1 Gb image, and a client boots, it might read just 20-50 Mb
It would store those on the stick, so the next time it booted it would just have to ask the server "has this part changed? no? then I'll read it from the stick, don't send it to me over the network"


dgroos:* Right.* And stick access is pretty quick!
How much work/time do you see setting up something like this would take someone in-the-know?

alkisg:* And scales well. And local disks could also be used (e.g. ntfs partitions), if available

*A lot, implementing properly a caching file system over the network is no easy task. E.g. that caching nfs-client was implemented but abandoned, I'm sure there's a reason behind it abandonment

dgroos:* I wonder how important this feature would be to other educators?


alkisg:* A lot, it'd be useful for 100mbps networks too, and if implemented properly (with caching ldap) it would even allow a classroom to be still used when a server goes down
(not exactly ltsp anymore...)


dgroos:* It seems there would be *lots* of overlap, however.

alkisg:* I think in Spain they chose to sync the image from the server on each boot instead of using ltsp, I imagine if such a thing was implemented they would use it too (thousands of installations there)


dgroos:* There site is powered by plone... http://www.guadalinex.org/que-es-guadalinex

vmlintu:* Maybe the ltsp image could be sync'ed in initramfs to local hard drive

That might be worth a try.. it'd take quite a long time to transfer a 10 gig fat client image, though..

dgroos:* How often would this have to happen?

vmlintu:* every time the image changes, I guess
Using rsync would probably shorten the time quite a bit, though


dgroos:* could it be only the part that had changed--incremental I'm trying to say, somehow?

vmlintu:* rsync transfers only the parts that have changed - we use that now to transfer ltsp images to our servers


dgroos:* OK.* Could one use USB sticks instead of HD to increase speed, significantly?

vmlintu:* most usb sticks I have tried have been slower than hard drives

alkisg:* dgroos: are you mainly talking about thin or fat clients?


alkisg:* Because if you have enough bandwidth for thin clients (sending videos, X traffic etc) it would more than cover the networked-disk part... not much need for caching there

dgroos:* Well, I'm very big into recycling older Pentium 3 and 4 machines so I would say for the near future thin clients using lots of localapps, but if it were just pentium 4's with a gig of RAM I'd say fat clients for sure.


alkisg:* dgroos: nice, but as in the local ministry proposal, I'd prefer a little larger tables, with an ltsp server on the bottom of each table
This way the netbooks/pcs/tablets/whatever there could have wired connections to the ltsp server, and the server be wirelessly connected to the internet


dgroos:* Excellent idea with the local ltsp server!
*I could make that work, maybe...
Would a pentium 4 with 1 gig ram be enough for a 3-computer ltsp server?* Would sch-scripts still work on them?
would it need a gig NIC?


alkisg:* That server could have 3x100mbps network cards, I think that'd be cheaper than gigabit+switch+whatever
*sch-scripts would work, sure
About the pentium 4 with 1 gb ram... well it would work, but I don't know if you'd be satisfied with the performance


dgroos:* How about the performance if the other 3 were running as fat clients?* as localapps? if the server had 2 gigs ram?* I know you don't know from experience--just asking your best guess.

alkisg:* For fat clients, you can have a very old ltsp server with just 512 MB RAM and a fast disk

No cpu/much ram is needed there
Of course if you have 2 Gb, it'll be used for caching...

dgroos:* regular 7200 fast *enough*?

alkisg:* Sure

dgroos
:* I'll be doing tests on this in the next couple of months and report back

dgroos: I'll post related parts of this to my question on the list serve as well.

alkisg:* dgroos: have you ever checked multiseat?
It allows a single pc to have lots of screens + mice + keyboards
Check the video there: http://www2.userful.com/products/userful-multiseat-linux

There are multiple implementations, I just gave the link for the nice video

dgroos: Thanks!* I'll be checking that out as well, and adding some notes to my blog...
[4:58PM] dgroos: Thanks alkisg, vmlintu and mhall119!

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Old 01-10-2011, 12:34 AM
Michael
 
Default LTSP over wireless?

I'd think that the biggest problem with LTSP over wireless would be
finding a wireless card or minimal boot image capable of initiating a
connection to the correct AP (how does it know the right one?) and
authenticating (if using WEP or WPA).


--
Michael Hall
mhall119@gmail.com



On Sun, 2011-01-09 at 17:41 -0600, David Groos wrote:
> Hi All,
> Here's an update on this topic from the discussion on the edubuntu
> channel today. I edited it a bit for brevity and focus and ease of
> reading. This will be useful to document the ideas given.
> David
>
>
> alkisg: LTSP over wireless will be kinda slow, maybe *nx would fare
> better
>
> dgroos: Possible, though? How about with gigabit wireless with a
> ratio of 1 router to 10 clients?
>
> alkisg: Sure, it's possible, as long as you have an appropriate
> initramfs locally, e.g. in a usb stick
> To check if the performance suffices, you can temporarily test with
> XDMCP, it has the same performance as ltsp
> I.e. enable xdmcp in /etc/gdm/custom.conf, and run X -query on e.g. 10
> standalone clients over wireless
> I've never seen a gigabit wireless link so I don't know how that would
> perform
>
> vmlintu: fat clients might perform better over wireless
>
> dgroos: Right, wireless N is rated at 300 MB/sec...
> Thanks for the ideas to try the XDMCP, I'll give that a go in the
> coming month or 2 and get back to the list.
> thanks for the idea--I would just need an additional 512 MB ram for
> each thin client I'm on and they should work fine (Pentinum 4's).
>
> vmlintu: I should do some testing with fat clients over wireless some
> day too
>
> alkisg: Some form of local image cloning + syncing is needed there,
> otherwise with regular 50mbps wireless they're slow
> I read a paper once about a modified nfs client that used lots of
> local caching, that would be ideal but I don't think they're
> maintaining it after the initial implementatino
>
> mhall119: IIRC, samba does a good job of local caching
>
> alkisg: mhall119: that persists across reboots?
>
> mhall119: probably not, no
>
> alkisg: That wouldn't help then
>
> dgroos: when you say 'local image cloning + syncing' do you mean that
> the disk image would be stored on the USB flash drive, and that that
> image would be synched during each session?
>
> alkisg: yes, but ideally it wouldn't need to be synced as a whole, but
> only the parts that the clients needs to read each time
> So it wouldn't add any boot or other overhead
> E.g. the user would say "reserve 1 Gb on that usb stick for caching",
> and that'd be all, even if the fat client image was 10 Gb.
>
> dgroos: So, this is LTSP with a fat client but 'X' is stored locally
> on a USB stick, with the parts of X updated as needed. Not quite sure
> what this, "X" is, yet. Are you saying that the USB stick would have
> 10 GB on it or 1 GB?
>
> alkisg: 1
> dgroos: ... So, the incrementally updated image might be about 1 gig
> only. This 'cached' info, that's on RAM? Thus the need for more than
> 2 GB RAM? Or that could be on the USB stick?
>
> alkisg: No no it's not related to RAM, I just tried to give a similar
> example
> The clients wouldn't need any additional RAM for that, the cache
> would be on the usb stick, stored asynchronously so that it wouldn't
> add any overhead
> E.g. when you have an 1 Gb image, and a client boots, it might read
> just 20-50 Mb
> It would store those on the stick, so the next time it booted it would
> just have to ask the server "has this part changed? no? then I'll read
> it from the stick, don't send it to me over the network"
>
> dgroos: Right. And stick access is pretty quick!
> How much work/time do you see setting up something like this would
> take someone in-the-know?
>
> alkisg: And scales well. And local disks could also be used (e.g.
> ntfs partitions), if available
> A lot, implementing properly a caching file system over the network
> is no easy task. E.g. that caching nfs-client was implemented but
> abandoned, I'm sure there's a reason behind it abandonment
>
> dgroos: I wonder how important this feature would be to other
> educators?
>
> alkisg: A lot, it'd be useful for 100mbps networks too, and if
> implemented properly (with caching ldap) it would even allow a
> classroom to be still used when a server goes down
> (not exactly ltsp anymore...)
>
> dgroos: It seems there would be *lots* of overlap, however.
>
> alkisg: I think in Spain they chose to sync the image from the server
> on each boot instead of using ltsp, I imagine if such a thing was
> implemented they would use it too (thousands of installations there)
>
> dgroos: There site is powered by plone...
> http://www.guadalinex.org/que-es-guadalinex
>
> vmlintu: Maybe the ltsp image could be sync'ed in initramfs to local
> hard drive
> That might be worth a try.. it'd take quite a long time to transfer a
> 10 gig fat client image, though..
>
> dgroos: How often would this have to happen?
>
> vmlintu: every time the image changes, I guess
> Using rsync would probably shorten the time quite a bit, though
>
> dgroos: could it be only the part that had changed--incremental I'm
> trying to say, somehow?
>
> vmlintu: rsync transfers only the parts that have changed - we use
> that now to transfer ltsp images to our servers
>
> dgroos: OK. Could one use USB sticks instead of HD to increase
> speed, significantly?
>
> vmlintu: most usb sticks I have tried have been slower than hard
> drives
>
> alkisg: dgroos: are you mainly talking about thin or fat clients?
>
> alkisg: Because if you have enough bandwidth for thin clients
> (sending videos, X traffic etc) it would more than cover the
> networked-disk part... not much need for caching there
>
> dgroos: Well, I'm very big into recycling older Pentium 3 and 4
> machines so I would say for the near future thin clients using lots of
> localapps, but if it were just pentium 4's with a gig of RAM I'd say
> fat clients for sure.
>
> alkisg: dgroos: nice, but as in the local ministry proposal, I'd
> prefer a little larger tables, with an ltsp server on the bottom of
> each table
> This way the netbooks/pcs/tablets/whatever there could have wired
> connections to the ltsp server, and the server be wirelessly connected
> to the internet
>
> dgroos: Excellent idea with the local ltsp server!
> I could make that work, maybe...
> Would a pentium 4 with 1 gig ram be enough for a 3-computer ltsp
> server? Would sch-scripts still work on them?
> would it need a gig NIC?
>
> alkisg: That server could have 3x100mbps network cards, I think
> that'd be cheaper than gigabit+switch+whatever
> sch-scripts would work, sure
> About the pentium 4 with 1 gb ram... well it would work, but I don't
> know if you'd be satisfied with the performance
>
> dgroos: How about the performance if the other 3 were running as fat
> clients? as localapps? if the server had 2 gigs ram? I know you
> don't know from experience--just asking your best guess.
>
> alkisg: For fat clients, you can have a very old ltsp server with
> just 512 MB RAM and a fast disk
> No cpu/much ram is needed there
> Of course if you have 2 Gb, it'll be used for caching...
>
> dgroos: regular 7200 fast *enough*?
>
> alkisg: Sure
>
> dgroos
> : I'll be doing tests on this in the next couple of months and report
> back
> dgroos: I'll post related parts of this to my question on the list
> serve as well.
>
> alkisg: dgroos: have you ever checked multiseat?
> It allows a single pc to have lots of screens + mice + keyboards
> Check the video there:
> http://www2.userful.com/products/userful-multiseat-linux
> There are multiple implementations, I just gave the link for the nice
> video
>
> dgroos: Thanks! I'll be checking that out as well, and adding some
> notes to my blog...
> [4:58PM] dgroos: Thanks alkisg, vmlintu and mhall119!


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Old 01-10-2011, 10:27 PM
Joseph Bishay
 
Default LTSP over wireless?

Hello,

I came across this link about a year ago or so, and while I wasn't
looking for how to do wireless LTSP, I thought perhaps it might be
useful so I bookmarked it. My apologies if you're already seen it.

http://www.sarathlakshman.info/2010/03/14/wireless-ltsp/

Thanks
Joseph

On Sun, Jan 9, 2011 at 11:41 AM, David Groos <djgroos@gmail.com> wrote:
> My research tells me that LTSP hasn't been officially supported over
> wireless connections, but that it's possible if you put a minimum kernel on
> a flash drive, and initiate the boot from there, though this then isn't
> really an LTSP system.* I see some comments on forums and list-archives but
> many are from years ago.
>
> Since I don't know all of the technological underpinnings of all of the
> involved systems, I'm asking those of you who do know these technologies (or
> enough to weigh in): have wireless boot possibilities changed with the
> advances of wireless and networking and hardware and Ubuntu?* Is wireless
> thin/localapp/fat client/drbl on the horizon?* This is important to know as
> it opens up many options.
>
> Thanks,
> David
>
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Old 01-10-2011, 10:27 PM
Joseph Bishay
 
Default LTSP over wireless?

Hello,

I came across this link about a year ago or so, and while I wasn't
looking for how to do wireless LTSP, I thought perhaps it might be
useful so I bookmarked it. My apologies if you're already seen it.

http://www.sarathlakshman.info/2010/03/14/wireless-ltsp/

Thanks
Joseph

On Sun, Jan 9, 2011 at 11:41 AM, David Groos <djgroos@gmail.com> wrote:
> My research tells me that LTSP hasn't been officially supported over
> wireless connections, but that it's possible if you put a minimum kernel on
> a flash drive, and initiate the boot from there, though this then isn't
> really an LTSP system.* I see some comments on forums and list-archives but
> many are from years ago.
>
> Since I don't know all of the technological underpinnings of all of the
> involved systems, I'm asking those of you who do know these technologies (or
> enough to weigh in): have wireless boot possibilities changed with the
> advances of wireless and networking and hardware and Ubuntu?* Is wireless
> thin/localapp/fat client/drbl on the horizon?* This is important to know as
> it opens up many options.
>
> Thanks,
> David
>
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Old 01-12-2011, 02:37 AM
David Groos
 
Default LTSP over wireless?

Thanks Joseph, I hadn't seen this.* Most of it is for programmers so I'll have to e-mail him and ask him about where the solution is at.* Any programmer want to look at this page?* It's a blog entry of a college/grad student describing his project on how he made LTSP work over wireless.


David

On Mon, Jan 10, 2011 at 5:27 PM, Joseph Bishay <joseph.bishay@gmail.com> wrote:

Hello,



I came across this link about a year ago or so, and while I wasn't

looking for how to do wireless LTSP, I thought perhaps it might be

useful so I bookmarked it. *My apologies if you're already seen it.



http://www.sarathlakshman.info/2010/03/14/wireless-ltsp/



Thanks

Joseph



On Sun, Jan 9, 2011 at 11:41 AM, David Groos <djgroos@gmail.com> wrote:

> My research tells me that LTSP hasn't been officially supported over

> wireless connections, but that it's possible if you put a minimum kernel on

> a flash drive, and initiate the boot from there, though this then isn't

> really an LTSP system.* I see some comments on forums and list-archives but

> many are from years ago.

>

> Since I don't know all of the technological underpinnings of all of the

> involved systems, I'm asking those of you who do know these technologies (or

> enough to weigh in): have wireless boot possibilities changed with the

> advances of wireless and networking and hardware and Ubuntu?* Is wireless

> thin/localapp/fat client/drbl on the horizon?* This is important to know as

> it opens up many options.

>

> Thanks,

> David

>

> --

> edubuntu-users mailing list

> edubuntu-users@lists.ubuntu.com

> Modify settings or unsubscribe at:

> https://lists.ubuntu.com/mailman/listinfo/edubuntu-users

>

>



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