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Sharing disk space between servers
by Mark Rogers 27 Jun '22

27 Jun '22

I have several virtual servers with the same provider. Typically I have around 50GB disk space. On some I have largish databases, with consequently large database backups. The backups are for recovery from cock-ups rather than disaster recovery so retaining them on the same server is convenient, but they do tie up disk space, and the ones with the biggest databases lose the most to database backups. So ideally I want to do something to share the spare capacity on other servers, but safely. for example in the event that one server got hacked I don't want that to provide a backdoor to another server, and nor should any data that's been shared onto it be easily accessible. In an ideal world, it would be nice to ring fence (say) 15GB of capacity on server A and make it available over the network to server B such that A can't access B's files even though they're stored there (I accept that I can't stop someone with root on A deleting the files, but they should at least be encrypted so that they can't be read). And whilst B can use that allocated chunk of A's disk, it must not be able to access anything else on A. Ideally the capacity that's shared should be pretty easy to change so I can easily adapt if A needs more space. (I wondered about trying to remotely mount an encrypted file on A as a filesystem on B, but adapting the size later would be difficult.) As anything I do will be making changes to already functioning servers A & B the changes need to be relatively narrow to avoid the risk of breaking something. Thoughts / suggestions / experience of doing something like this? I can think of various paths to take, from simply pushing files over scp and working out how best to secure it (and manage the quota), to something far more complex like GlusterFS, with lots of options in between. So it's not really a lack of ideas as any idea which ones would be best! -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0344 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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Editing files on remote servers over SSH
by Mark Rogers 26 Jun '22

26 Jun '22

What's the best way to edit files on remote servers over SSH? Using a text editor directly over SSH is fine, but a GUI editor like VSCode is easier to work with. But I never have much luck getting SSH/SFTP plugins to work reliably, so I wondered what other people do. Preferably cross-platform as I have to switch between platforms a lot. -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0344 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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SSD HDD and simlinks?
by Phil Thane 01 Jun '22

01 Jun '22

After plaguing this list for months about my ailing desktop PC I finally skipped it and bought a (basic) new one. It comes with 128GB SSD. It's fast of course but not very big. So here's the plan but any advice would be good... I took the (almost new) 1TB drive out of the old PC and there's a lot of stuff on it. I've fitted it to the new machine but not installed anything yet as my ancient keyboard with a PS2 plug won't fit! Once that's sorted I'll install Mint. I *think* I'll do a standard install to the SSD and ignore the HDD. My user data on the HDD is mostly in /home/phil/Nextcloud and it was synced to my Nextcloud server. I assume, hope, I can keep that synced data on the HDD and just link the directory to my new /home/phil/... Not sure if that means using the link as the Nextcloud directory when setting up the client or maybe Nextcloud will allow me to connect direct to the HDD. Either way though I'm hoping to avoid taking all day to sync my data across the network. I remember long ago having a PC with 2 small HDD and setting it up with / on one but /home on the other. Is that still a thing? Is it worth doing in this case? Though bearing in mind it means formatting the HDD and re-syncing all the data. -- Phil

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Re: Comparing large folders of mostly identical file contents with different filenames (Mark Rogers)
by Peter 31 May '22

31 May '22

A query, not a suggestion, because you are all far, far better informed than me about this stuff! I was curious and looked up what tools are available for this, and came on: rdfind Fdupes dupGuru which all seem to find dupes by content. I am sure Mark is well aware of these and more. So why can't one of them be used to find the dupes? Also, is any of them significantly better than the others? Different but related issue, the app I have used to sync folders in the past is Unison, which I found very simple and effective. Also Grsync. Do people use these? Or is something else preferable? Peter On Sun, 22 May 2022 12:00:03 +0100 main-request(a)lists.alug.org.uk wrote: > Send main mailing list submissions to > main(a)lists.alug.org.uk > > To subscribe or unsubscribe via email, send a message with subject or > body 'help' to > main-request(a)lists.alug.org.uk > > You can reach the person managing the list at > main-owner(a)lists.alug.org.uk > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of main digest..."

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Sharing 2FA (TOTP)
by Mark Rogers 31 May '22

31 May '22

Are there any good ways of sharing 2 factor authentication credentials? Scenario: I have probably 20 accounts secured by 2FA using (currently) Authy to manage them. A colleague similarly has their own 2FA setup (not sure what they use). However there are some accounts we both need access to, and therefore at present we haven't enabled 2FA on. I want to set up 2FA in such a way that either of us can generate a code without sharing anything else to do it. I believe this is using TOTP protocol? I don't know enough about how it works but I can't see any technical reason why the shared secret can't be shared between multiple people (Authy already lets me share between multiple devices, but in an "all or nothing" way.) Obviously sharing 2FA credentials weakens security. But at present the alternative is not using it at all, and surely shared 2FA is better than that. -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0344 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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Comparing large folders of mostly identical file contents with different filenames
by Mark Rogers 23 May '22

23 May '22

I have a backup of a GMail account which creates folders by year, month, date and within them .eml files for each email. I'm migrating to a different GMail account so I'm moving the emails to the new account, and I have a backup also of the second account. So it's something like: Account1/2022/5/1/aaaa.eml and Account2/2022/5/1/bbbb.eml .. with each being identical emails (a diff of the two files will confirm that). Of course I don't just have 1 email. I have about 200,000, and the number of files in the two backups is slightly different so I want to find the discrepancies. So: Any suggestions? I could run a standard dedup program but that'll be very slow given that it'll be comparing 200k files with another 200k files. In most cases I suspect the missing file(s) will stand out just from their file sizes on a per-directory comparison. -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0344 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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RAM
by Phil Thane 17 May '22

17 May '22

Hi, Over the last few months I've posted a few enquiries about my steadily worsening PC. A few tweaks have sometimes improved things slightly for a while but long term it's getting worse. It's now very unstable given to hanging whenever asked to do anything like move/close a window, so hope I get to the end of this without a problem. I *think* there might be a problem with RAM and/or mainboard RAM slots. There are 2x4GB modules fitted. (Crucial Ballistix not cheapo stuff). UEFI setup and lshw both report 8GB but free only shows 4GB. That was the case under Mint, and still is with a fresh install of Kubuntu. Any suggestions before I lash out on new RAM? Because if I do it's pretty much guaranteed to be something else. Or do any of you have old DDR 3 you've replaced with bigger sticks and not got around to selling on Ebay? Cheap preferred but no reasonable price refused! If all else fails I guess a new MoBo/CPU/RAM bundle might be required... -- Phil

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Re: RAM
by Srdjan Todorovic 13 May '22

13 May '22

On Fri, 13 May 2022 at 19:59, Phil Thane <phil(a)pthane.co.uk> wrote: > > Memtest isn't installed and isn't available from Ubuntu repositories. > probably could get it from elsewhere but chances are I just crash/hang > the thing again! Memtest is supposed to be booted off a usb drive or a cd. You can get it from https://www.memtest.org/archives and get version 5.31, follow the instructions to write that to a bootable media and then test the ram. Secondary computer you could use? > Kubuntu system monitor shows 4GB but no error messages, and trying to > run it just hung the PC again so doing this from a different machine. Nothing in the kernel logs? dmesg? No exotic PCI cards in the system or other experimental drivers loaded? > uname -a shows kernel version 5.15.x.x and AMD X86-64 > > Can't see anything in UEFI to suggest setting problem. It shows 8GB > installed and 8GB available. Suggests your linux install is messed up? Can you reinstall or re-download the ISO again, verify that the ISO is not corrupted and burn another install disk and try re-installing? > On 13/05/2022 19:41, Srdjan Todorovic wrote: > > On Fri, 13 May 2022 at 19:30, Phil Thane <phil(a)pthane.co.uk> wrote: > > > >> It's now very unstable given to hanging whenever asked to do anything > >> like move/close a window, so hope I get to the end of this without a > >> problem. > > What does Memtest86 say about your ram? This should be the very first > > thing you do. > > > >> I *think* there might be a problem with RAM and/or mainboard RAM slots. > >> There are 2x4GB modules fitted. (Crucial Ballistix not cheapo stuff). > >> UEFI setup and lshw both report 8GB but free only shows 4GB. That was > >> the case under Mint, and still is with a fresh install of Kubuntu. > > Which version of Kubuntu? > > What kernel version and architecture? uname -a > > > > Are you sure your kernel is not 32bit without PAE extensions? That > > would limit to 4GB usable RAM even if you had more. > > Any weird BIOS / UEFI settings that might put it into some sort of > > legacy mode to only give you 4GB? > > > >> Any suggestions before I lash out on new RAM? Because if I do it's > >> pretty much guaranteed to be something else. Or do any of you have old > >> DDR 3 you've replaced with bigger sticks and not got around to selling > >> on Ebay? Cheap preferred but no reasonable price refused! > > I have 2 sticks of 4GB each, DDR3 ECC server ram - not sure if it > > would work (you would need to check if your CPU + motherboard could > > support it), but might be open to taking £10 or something + postage? I > > would need to do Memtest86 on that ram to make sure it's ok. > > > > Thanks, > > Srdjan

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"Upgrading" Ubuntu via fresh install
by Mark Rogers 25 Apr '22

25 Apr '22

Over the years I have upgraded my Ubuntu desktop twice a year using do-release-upgrade. My root drive SSD is nearly full so I've just bought a bigger one, and I'm looking at migrating across to it. But... Ubuntu 22.04 is nearly here, so maybe it would make more sense to clean things up with a fresh 22.04 install on the new SSD instead? I know lots of people avoid upgrades and just do a clean install retaining /home (or something along those lines) but I've never done it myself. Is it the right way to go? It's a desktop PC, but 99% of the time I access it via SSH. Over the years it's had all sorts of stuff installed and uninstalled (or installed and no longer used but still there). So a clearout definitely seems like a good idea. So it seems like what I ideally want is a managed migration where I choose which things I have on the old install I migrate and which I leave behind. Is this going to be more hassle than it's worth? -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0344 251 1450 Registered in England (0456 0902) 21 Drakes Mews, Milton Keynes, MK8 0ER

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Re: "Upgrading" Ubuntu via fresh install (Martin Collins)
by Peter 24 Apr '22

24 Apr '22

I've been meaning to ask this question for a while, and this seems like a good occasion. I'm moving someone from a very old i3 machine to a new AMD machine. The key difference apart from performance is that the old machine was bios, and the new one is of course compulsorily EFI. So what I did was, do a new install, then use Clonezilla to make a copy of the /home partition, and moved it to the new machine. Everything seems fine, with one exception. The old machine is on Debian Mate. All the files seem to have moved fine. But desktop layout is a different matter. The user has an enormous desktop file on a quite large screen with every inch covered with folders, in a familiar order and positioning. Unfortunately the layout of the desktop doesn't seem to survive the transition, its alpha order. Where is the layout of the desktop file kept? And is there a way to keep its layout while doing the transfer? Its not the end of the world if it just has to be accepted, but it would make life a lot easier if I could keep it. This was never a problem in previous machine moves, because I made a clone of the hard drive, then booted on the new machine. But with the arrival of compulsory EFI this isn't possible any more. They have removed legacy mode on the new main board. I have looked up converting an installation from bios to EFI. It seems like a very fraught procedure. And after all these years there's a case to be made for a clean install, as people here have said. So if I could overcome the desktop layout problem that would be what I would rather do. Peter

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