March 2018 - luv-main

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

06 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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Using a Raspberry Pi in Education (Teaching)
by Said, Joseph J 01 Mar '18

01 Mar '18

Dear List Is anybody using a Raspberry Pi for teaching coding, hardware or any other application in a school? I have been asked to investigate the possibility. Thanks in advance. Joe Joe Said VCE IT / Mathematics / Science Teacher Assistant Daily Organiser Rosehill Secondary College IMPORTANT - This email and any attachments may be confidential. If received in error, please contact us and delete all copies. Before opening or using attachments check them for viruses and defects. Regardless of any loss, damage or consequence, whether caused by the negligence of the sender or not, resulting directly or indirectly from the use of any attached files our liability is limited to resupplying any affected attachments. Any representations or opinions expressed are those of the individual sender, and not necessarily those of the Department of Education and Training.

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