Simple use cases, howto guides, tutorials, update issues

    • OMV 2.x

    This site uses cookies. By continuing to browse this site, you are agreeing to our Cookie Policy.

    • Simple use cases, howto guides, tutorials, update issues

      Looks great project, just building my system, 64bit Athlon, installed software on HD, about to add Tbyte drives, but I'm having difficulty finding where the documentation is, my noob documentation foo is not strong. I especially answers to questions like 'If I want to get a system that does *this*, then how should I achieve it?' I am reluctant to just start in hoping and poking without knowing what I'm doing, or what best practice is.

      At present, I have 2 data discs, which as time goes on, I expect to add to. If I add a further disc, is OMV capable of migrating the data from a 2 disc system to a 3 disc raid5 automatically (and eventually an 8 disc raid 6) and does it make a difference whether I start with raid 1, raid 5, or one disc with rsync to the second? Are there other reasons than future migration to choose between the 3 different ways of starting with 2 discs.

      If my system breaks, I presume I can build a new one and transfer my data discs to it, and read them without having to reformat them and lose the data? I can't imagine the reason for storing data like this if I can't. Can I save a RAID configuration file or something?

      During installation, I didn't have network available, so didn't set up update mirrors. I have now got network, and can access webGUI, but attempting to check for updates fails with a

      'Failed to execute command 'export LANG=C; apt-get update 2>&1': Ign file: Release.gpg Ign file: Release Ign cdrom://[Debian GNU/Linux 7.0.0 _Wheezy_ - Official Snapshot amd64 LIVE/INSTALL Binary 20150629-08:52] wheezy Release.gpg Err packages.openmediavault.org stoneburner Release.gpg Something wicked happened resolving 'packages.openmediavault.org:http' (-5 - No address associated with hostname) ...'

      and it carries on in like vein referring to another 8 or so files. Is this a mirror issue, or something else?

      Sorry for asking idiot questions, but from the bottom of the learning curve here, it looks a long way up.
    • Neil_UK wrote:

      I'm having difficulty finding where the documentation is
      Most of it is in the forums. Try here first. Otherwise, using google to search just the forum works for me. Because there are millions of ways to setup a system, it would be hard to write a document that covers all of it. Just ask question in the forum when you are stumped.

      Neil_UK wrote:

      does it make a difference whether I start with raid 1, raid 5, or one disc with rsync to the second?
      You definitely can't migrate from raid 1 to raid 5 with the web interface.

      Neil_UK wrote:

      If my system breaks, I presume I can build a new one and transfer my data discs to it, and read them without having to reformat them and lose the data? I can't imagine the reason for storing data like this if I can't. Can I save a RAID configuration file or something?
      Re-installing will not cause data loss. That is why the OS and data disks are separate. Raid config is stored on the raid array members.

      Neil_UK wrote:

      Is this a mirror issue, or something else?
      Fix your sources.list. Read this. Just make sure to read all of it!
      omv 4.1.9 arrakis | 64 bit | 4.15 proxmox kernel | omvextrasorg 4.1.9
      omv-extras.org plugins source code and issue tracker - github

      Please read this before posting a question and this and this for docker questions.
      Please don't PM for support... Too many PMs!
    • Thanks ryecoaaron, reading deeply now.

      I read the entire link to fix the sources, the sources builder page generated this ...

      Python Source Code

      1. #------------------------------------------------------------------------------#
      2. # OFFICIAL DEBIAN REPOS
      3. #------------------------------------------------------------------------------#
      4. ###### Debian Main Repos
      5. deb http://ftp.uk.debian.org/debian/ wheezy main contrib non-free
      6. ###### Debian Update Repos
      7. deb http://security.debian.org/ wheezy/updates main contrib non-free
      8. deb http://ftp.uk.debian.org/debian/ wheezy-proposed-updates main contrib non-free


      ... which I put into /etc/apt/source.list

      When I try to 'check' in the update manager, I still get ...

      Failed to execute command 'export LANG=C; apt-get update 2>&1': Ign file: Release.gpg Err packages.openmediavault.org stoneburner Release.gpg Something wicked happened resolving 'packages.openmediavault.org:http' (-5 - No address associated with hostname) Ign file: Release Err ftp.uk.debian.org wheezy Release.gpg Something wicked happened resolving 'ftp.uk.debian.org:http' (-5 - No address associated with hostname) Err ftp.uk.debian.org wheezy-proposed-updates Release.gpg Something wicked happened resolving 'ftp.uk.debian.org:http' (-5 - No address associated with hostname) ... and so it goes on ...




      Clarification of RAID styles and how OMV can handle them ...

      I've got that for a two disk system, I might as well cron rsync to the second disk.

      When I come to add a third disk and want to go raid 5, can it automatically build the raid around the existing single disk's worth of data, or do I need a 4th disk to move the data out of the way?

      If I have a 3 disc raid 5, is it correct that I can add a 4th disc, and it can migrate to a 4 disk raid 5 around the data?

      I would strongly suspect that adding another disc to a raid 5 to get to a raid 6 is trivial, as it's the second parity disc that needs to get built.

      The post was edited 2 times, last by Neil_UK ().

    • Neil_UK wrote:

      I've got that for a two disk system, I might as well cron rsync to the second disk.
      I actually think most users would be better off with this than raid. A lot of people want to use raid as backup.

      Neil_UK wrote:

      When I come to add a third disk and want to go raid 5, can it automatically build the raid around the existing single disk of data, or do I need a 4th disk to move the data out of the way?
      Nope. Raid doesn't use filesytems on each individual disk. So, everything needs to be recreated.


      Neil_UK wrote:

      If I have a 3 disc raid 5, is it correct that I can add a 4th disc, and it can migrate to a 4 disk raid 5 around the data?
      You can easily add additional disks with the add button in the web interface. Converting to raid 6 would require the command line.

      Do you really need the raid redundancy or are you just trying to pool the drives? I strongly recommend the union filesystem plugin (I use it myself) over raid. I use the rsnapshot plugin to backup the data. With the union filesystem plugin, if a drive fails you only lose data on that drive (with a backup, you don't really lose anything) and the pool keeps working.
      omv 4.1.9 arrakis | 64 bit | 4.15 proxmox kernel | omvextrasorg 4.1.9
      omv-extras.org plugins source code and issue tracker - github

      Please read this before posting a question and this and this for docker questions.
      Please don't PM for support... Too many PMs!
    • Any thoughts on why I'm still getting failure to be able to update (details in previous post)? What can I do for further investigation? I am using the google DNS at 8.8.8.8 in my network setup, it pings at 27mS, so it's visible.

      I'm not trying to pool the drives, I want drive failure redundancy. In support of which, I presume OMV can do a drive integrity check, and/or file compare across both disks?
    • Neil_UK wrote:

      Any thoughts on why I'm still getting failure to be able to update (details in previous post)? What can I do for further investigation? I am using the google DNS at 8.8.8.8 in my network setup, it pings at 27mS, so it's visible.
      DNS isn't resolving. Switch to dhcp to see if it works. Or try using your router as the dns server.

      Neil_UK wrote:

      I presume OMV can do a drive integrity check, and/or file compare across both disks?
      Not sure what should be doing either of those. Are you talking about a RAID 1 array still?
      omv 4.1.9 arrakis | 64 bit | 4.15 proxmox kernel | omvextrasorg 4.1.9
      omv-extras.org plugins source code and issue tracker - github

      Please read this before posting a question and this and this for docker questions.
      Please don't PM for support... Too many PMs!
    • So you think it could be DNS as well? I'll try bugging around in that area, and if still not, try a re-install with the network up this time.



      Drive integrity / file compare ?

      I'm new(ish) to Linux, so really don't know what's available. While I can read man pages, and wade through the piles of switches, that's a mapping from 'feature' to 'will it do my job', rather than 'my use case is' to 'how do I make it do that?' When I came to set up samba for my PI, for a tiny media server, there was some very useful 'this is how you build a this, this is how you build a that' type documentation available.

      As I'm building a large enough multi-disk system for a protection of my data against disc failure, I want to know as soon as possible if a drive is going bad, rather than just not being able to serve the specific file I've asked for at that moment. I'm not too bothered what configuration I use, just whether it will fit my use case well.

      Let's assume I'm using JBOD with a periodic rsync from the primary to the secondary disc. Does OMV have some facility built in where it can check all files, or indeed the physical device for integrity, in other words, to meet my need for early warning of a large scale failure. Perhaps rsync can provide a check like that through an option, as it's already doing the right sorts of things? I am surely not the first person to consider the possibility of disk failure in a multidisk system? What's best practice?

      It appears that for my low data volumes, RAID is not worth it now. I suspect that by the time I come to expand the file system, prices will have changed so that buying one new big disc and staying with rsync will be cost effective against using smaller discs, and easier to migrate the data without using any extra storage.
    • Sorry, I was just clarifying what you were looking for.

      What you want to predict drive failure is SMART. And yes, OMV has a SMART tab where you can run regularly scheduled drive tests.

      Rsync can also do checksums to make sure files are ok.

      I would also check into snapraid (there is a plugin for it) as it will check file integrity and give you some drive redundancy as well.
      omv 4.1.9 arrakis | 64 bit | 4.15 proxmox kernel | omvextrasorg 4.1.9
      omv-extras.org plugins source code and issue tracker - github

      Please read this before posting a question and this and this for docker questions.
      Please don't PM for support... Too many PMs!
    • SMART sounds promising, and I've read up on rsync a bit, so it looks like something can be got to work.

      I played around with DNS's, my ISP's, google, OpenDNS, auto with DHCP, nothing. So I reinstalled everything from scratch with the network connected at install time, and it's now working, and updated.

      Thanks for all your help. Time to install the data disks.