On Monday, 5 March 2018 10:15:35 PM AEDT Andrew Greig via luv-main wrote: > 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?
Sure. But it's easier to have RAID for everything. > sda is 1Tb and sdb and sdc are identical Seagate SATA drives of 2Tb each. If you had memory limits then you could use one disk for swap and the others for data access. But memory limits aren't much of an issue nowadays, systems with 8G of RAM are often thrown out as rubbish and systems that can be expanded to 16G also appear in the rubbish. My main server in Melbourne has 16G of RAM and came from the InfoXchange rubbish pile. My workstation also came from the InfoXchange rubbish pile and has 8G in 2*4G DIMMs, I have systems from rubbish that would take 4*4G DIMMs but they have slower CPUs. When I attend the LUV meetings at InfoXchange I hunt through the rubbish pile for nice systems and offer them to anyone there. There seems to be a correlation between not having nice hardware at home and not being able to recognise nice hardware in a pile of rubbish. ;) More drives means more heat produced and more potential problems in summer. It means more parts that can fail and cause you annoyance. If you are about to buy new disks then getting 2*3TB seems like a better option than 1TB+2*2TB. If you are worried about data loss then latent sector errors is what you should worry about. I've replaced lots of disks in production due to them returning bat data and claiming it to be good. I can't remember the last time I replaced a disk in production due to it giving read errors. The vast majority of disk problems I've had in the last 10 years were only discovered because of using ZFS or BTRFS and would have given silent data corruption on any other filesystem. BTRFS allows you to use RAID-1 across any combination of disks. So if you put in 1TB+2*2TB in a BTRFS RAID-1 you would get 2.5TB of RAID-1 storage. BTRFS also allows you to dynamically resize arrays. You can start with a single disk, add another to make it RAID-1 (with a long operation of copying all the data) and then keep adding disks when you run out of space. > 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. Try to avoid getting one of the rubbish SSDs. My workstation has a Sandisk SSD, a Samsung, and an Intel all in a BTRFS RAID-1. The Sandisk SSD slows the entire system down, it can't handle 30MB/s of continuous writes so when I copy data from a USB-2 attached device the bottleneck is the Sandisk not USB 2.0. Intel and Samsung devices can be relied on to be reasonably good. Read reviews if you are thinking of buying another brand. 2*250G SSD costs about the same as 1*500G. Would a 250G RAID-1 of SSD be more useful than 500G of unmirrored storage? Even if you have only a single disk use BTRFS or ZFS. They both support multiple copies of metadata on a single disk and they both do checksums on everything so you know if anything gets corrupted. > Am I on the right track here or do I have incorrect expectations? Mostly right. -- My Main Blog http://etbe.coker.com.au/ My Documents Blog http://doc.coker.com.au/ _______________________________________________ luv-main mailing list luv-main@luv.asn.au https://lists.luv.asn.au/cgi-bin/mailman/listinfo/luv-main
