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disk usage in perl without modules or /bin/df
by Tim Connors 21 Mar '18

21 Mar '18

I have a very minimal system where I can't use df because I want an extended output df can't do, and I can't install CPAN modules (there isn't Filesys::Df, Filesys::Statfs, etc) I want it to take args of a given file/directory. stat()'s first returned arg is st_dev. What's a system call that can return current usage and total size of a dev? stracing df shows it does a stat then a statfs, but I can't seem to access the statfs system call from perl without Filesys::Statfs. Sigh, embedded (very large) systems. -- Tim Connors

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Re: quotas and reservations (was Re: Looking at RAID)
by Craig Sanders 12 Mar '18

12 Mar '18

On Fri, Mar 09, 2018 at 07:49:48PM +1100, Russell Coker wrote: > Unlike BTRFS, you can expect every feature of ZFS to just work. It may be > a total PITA to get it working, it may not be something you even want to ZFS just works, and I've never found it to be a PITA at all. I've been using it since around 2010. * `apt-get install zfs-dkms zfsutils-linux` (and optionally zfs-zed and zfsnap) is no big deal. It's no more trouble than installing anything else. * non-rootfs storage just works - no hassle, no fuss, no drama. Couldn't be easier...certainly a lot less work/hassle than LVM and/or mdam + ext4 or xfs. * getting linux to boot from ZFS requires some work (unless your distro supports it natively, like Ubuntu). A few hours of reading and about the same of careful, methodical work the first time you do it. IMO it's worth the effort just for snapshots & zfs send backups of the rootfs. All the other ZFS features are just gravy. > use (EG ZFS control of Samba configuration), but it will work if you do the > right thing. I've never used that. Or the auto-NFS stuff. I Never saw any need to try it since I was already running NFS and Samba - continuing to use what I already had was no trouble at all :) I don't really care about samba, but one of these days I should look into doing NFS exports just by setting an attribute on a dataset in zfs. For now, editing /etc/exports is easy enough. craig -- craig sanders <cas(a)taz.net.au>

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Re: Looking at RAID
by Paul Dwerryhouse 08 Mar '18

08 Mar '18

On 2018-03-07 11:44, Craig Sanders via luv-main wrote: > BTW, it's not always a good idea to follow install instructions from > developers. Many of them are focused exclusively on their pride and > joy and > don't give a damn about the operating system it runs on....and many see > the > OS as an obstacle to be worked around. Oh, so you mean that best practice for production installs *isn't* to run curl-pipe-sudo-bash that pulls something from the head of a random github repo and then runs npm to splatter it across your filesystem? ;)

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host name - domain name
by Nic Baxter 08 Mar '18

08 Mar '18

Hi All I host a number of domains on a Centos 7 VPS. Now I am setting up a VPS with only one domain hosted. I am trying to get my head around issues with naming especially regarding RDNS and a mail server. Should I name the server host.domain.com or just domain.com? Cheers Nic

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March 2018 Workshop: Comparing window managers
by Andrew Pam 07 Mar '18

07 Mar '18

Thanks to an excellent suggestion at yesterday's very successful March main meeting, this month's workshop on Saturday week (17 March) will be a comparison of Linux window managers. We're still looking for more people who can talk about the window manager they are using, what they like and dislike about it, and maybe demonstrate a little. Please email me with the name of your window manager if you think you could help! Thanks, Andrew

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Linux Distro for photographers.: Sony Alpha SLR/SLT A-mount Talk Forum: Digital Photography Review
by Andrew McGlashan 07 Mar '18

07 Mar '18

Hi Andrew, Thought this would be better in it's own thread. https://www.dpreview.com/forums/post/50166906 I can't vouch for the above, but a quick DDG search found it and it looks suitable (also based on OpenSuSE). Cheers A.

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Re: Looking at RAID
by Russell Coker 07 Mar '18

07 Mar '18

On Tuesday, 6 March 2018 6:29:11 PM AEDT Craig Sanders via luv-main wrote: > On Mon, Mar 05, 2018 at 10:54:10PM +1100, Andrew Pam wrote: > > [ ... ] it's also possible to set up mirroring using LVM, btrfs or ZFS > > if you prefer. > > With btrfs or ZFS it's easy to add additional drives for more space later. With ZFS you only add them one RAID set at a time and after adding that RAID set can't be changed. You can't just add a disk at a time as you do with BTRFS. Last time I checked BTRFS RAID-5 and RAID-6 wasn't reliable IMHO. > Also, both btrfs and ZFS support transparent compression - which can > greatly increase effective capacity if most of your data is uncomressed or > poorly-compressed. Not video or audio files, for example. The last time I ran a medium size mail server on ZFS I didn't see a lot of compression. I think it was something like 40%. Usually large amounts of data means video files though. > There are so many other benefits to using either btrfs or ZFS (snapshots, > error-detection and correction, sub-volumes aka datasets, and much more), > that IMO there's little reason to use a plain RAID-1 + ext4 partition for > anything except a separate /boot. Particularly as the most common errors are silent corruption which can't be detected by a plan RAID and can only be stopped by BTRFS or ZFS. Sucks for people who don't use Unix. > ZFS has the advantage of more features, and greater reliability. It's not > built in to the kernel, but most distros have the kernel module packaged as > a dkms package (ubuntu and a few others take the legally dubious stance > that the CDDL vs GPL license conflict isn't a problem, so include ZFS > pre-compiled with their kernels already). I don't think it's legally dubious. Oracle know exactly what they are doing, if Oracle thought it was bad they would have let them know. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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Re: Looking at RAID
by Russell Coker 06 Mar '18

06 Mar '18

On Tuesday, 6 March 2018 10:52:35 PM AEDT Andrew Greig via luv-main wrote: > Sorry about that digression. So is there a platform that handles RAID > really well? I went to OpenSuse for mapping. But now photography is my > main work, so maybe I should be looking at installing the distro which > is preferrred by developers of the GIMP and also Darktable. If you want to have root on a ZFS RAID then Ubuntu is likely to be the best option. But I recommend not doing that, it's more pain than you want IMHO. > I just can't afford to fiddle for two weeks to get a result. And the > OpenSuse and Ubuntu fora have freaked me out, somewhat. Setup a mdadm RAID-1 for /boot (and root in the case of ZFS) and then use ZFS or BTRFS for the rest. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/

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Hack evening
by Russell Coker 06 Mar '18

06 Mar '18

I'm running a FOSS hack evening tomorrow. Email me off list if you are interested in attending. -- Sent from my Huawei Mate 9 with K-9 Mail.

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Looking at RAID
by Andrew Greig 06 Mar '18

06 Mar '18

Hi all, My desktop computer hard drive is now full. I have offloaded a couple of hundred Gb to an external expansion drive to give me breathing space. So I am looking at keeping sda and if possible adding sdb and sdc as a RAID arrangement, from my reading I am leaning toward a software RAID 1 (mirrored drive) using SATA drives. I am progressing further along my intended path of returning to professional photography so data security is now imperative. Can I keep sda as my boot disk and just run sdb and sdc for data storage? sda is 1Tb and sdb and sdc are identical Seagate SATA drives of 2Tb each. I run OpenSuse Tumbleweed. I was intending to get an SSD of 500Gb for my post production work with output being stored only on RAID. Am I on the right track here or do I have incorrect expectations? Many thanks Andrew Greig

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