On Sun, Apr 05, 2015 at 01:19:46AM +1100, Russell Coker wrote:
On Sun, 5 Apr 2015, Andrew McGlashan <andrew.mcglashan@affinityvision.com.au> wrote:
A drive can fail day 1, day 90 or day 10,000 -- but in the end, they all fail eventually. You need multiple copies of data on multiple drives, or perhaps you'll get by with Russell's idea of using RAID1 on BTRFS, but I wouldn't trust that solution and it is limited to being used with Linux ... good or bad. You can use ext4 anywhere, even on Windows with the right drivers.
I wouldn't trust anything that only involves a single disk when given a choice. But when you do have to rely on a single disk using RAID-1 on that disk will significantly decrease the probability of data loss. This is why ZFS has the copies= option.
me either, to the point where i can't see the point of even bothering to backup to a single drive - it's just not reliable enough to deserve the label of "backup". IMO if you're going to do backup to disk, do it properly. it costs significantly more (i.e. at least two drives plus other hardware) but it's more than worth the cost and effort. That ASRock QC-5000 motherboard that Rick mentioned a week or so ago would make an ideal little ZFS NAS/backup-server. and at 15W, uses little enough power that it would cost bugger all to leave switched on and available on the network 24/7. it only has 4 SATA ports, but that's more than enough for a mirrored pair (i.e. like RAID-1) of drives. If more drives are required, you can pick up an 8-port SAS card on ebay for around $100 (not only superior to but much cheaper than multi-port SATA cards which often cost $300+ for only 4 ports - and you can plug SATA drives into a SAS port) pccasegear.com.au has the QC-5000-ITX for $145 and i've seen several other shops with the WIFI version of same for the same price - the linux driver for the WIFI card allows it to be used as an access point with hostap or just as a wifi client. http://www.pccasegear.com/index.php?main_page=product_info&cPath=138_1019&pr... pccasegear also has a quite nice looking mini-itx case with room for 6 x 3.5" drives (or 11 x 2.5" drives) for $99. doesn't include a power supply, but appears to take a standard ATX PSU. http://www.pccasegear.com/index.php?main_page=product_info&cPath=25_1119&pro... using a little 60GB SSD for linux + zfsonlinux (or maybe freebsd), and 8GB of RAM, that means you can have an excellent home NAS for around $350 (not including drives) that wipes the floor with crappy commercial NAS boxes that cost $800 or $1200 plus drives (built with the cheapest barely-adequate parts available to maximise profts and different product lines rather than to provide maximum utility & quality for least price). btw, ZFS works very nicely with samba and NFS, and they make for a convenient storage location for clonezilla backups of Windows, Mac, and Linux systems - and the ZFS server can also run a dhcp server as well as the TFTP and PXE-boot setup to have network-based debian (or whatever) installer, clonezilla, gparted, system-rescue-cd and other utilities. in fact, since it's a standard amd64 server running standard linux you can install whatever kind of server software you like on it - it's even powerful enough to run a few VMs. i have my zfs box set up to do this(*) and, while i don't need to use them frequently, having a network-bootable clonezilla or gparted has been a gnu-send :) on numerous occasions. and having a PXE-bootable debian-installer means i don't have to stuff around with CDs, DVDs, or USB sticks. (*) I pretty much duplicated the system i built at $previous_job to have a pxe-boot setup for gparted, d-i, sysrescd, and especially clonezilla for mass-producing windows & mac desktop machines for users. d-i was for the handful of postdocs etc who wanted linux desktops. although "duplicated the work setup" isn't entirely accurate - it's hard to say which came first, because I duplicated and improved my home PXE setup at work when i needed it, and then re-implemented some of the same ideas I came up with at work on my home setup - e.g. a set of scripts to download the latest clonezilla, extract it from the zip file, and generate the ipxe menu entries. and similar for gparted. i didn't bother with system-rescue-cd at home because i found i never used it much at work as both clonezilla and gparted make excellent rescue CDs in themselves. i use cz for almost everything, but gparted's graphical partition editor is useful when i need to do that kind of thing. craig -- craig sanders <cas@taz.net.au>