Rich Freeman <rich0 <at> gentoo.org> writes:
> > On 27/10/2014 11:24, Mick wrote: > >>> With a caveat: if an ssd dies, it will die suddenly. Without warning. With SSD the most important fact to keep constantly in mind is writing/erasing by blocks due to uniqueness of the hardware. Unfortunately, if you dig deeply, many Solid State Storage devices are organized differently and those hardware differences may impact your SSD_specific implementation details. SSD raid redundancy is something most machines (folks) cannot afford, imho and may be a waist to dis_functional if you employ the same semantics for I/O on the redundant SSD hardware. [1] http://codecapsule.com/2014/02/12/coding-for-ssds-part-6-a-summary-what-every-programmer-should-know-about-solid-state-drives/ > >> In such cases I am prepared to live with the risk of some > >> data loss, on machines where raid is not an option. Wise with a well thought out (planned) recovery/fresh-install strategy. > > Without some form of redundancy that would be your best strategy - > > decent and frequent backups > But yes, backup and RAID are really your only options for SSD failure > as far as I can see it. That and limiting the amount of data that > can't be re-generated. If you just save the world file and all of > /etc you could probably rebuild a Gentoo install fairly quickly on a > new drive, and then you're just left with /home and whatever else you > happen to have installed that sticks stuff in /var that you care > about. Yep. Rich has it exactly right. I'd add /usr/local/* as by design that is where I put most uniqueness in any linux system besides the list above. In fact for small networks, I just identify the directories that I want to preserve. At the least you rsysnc those to a differnet system on the local net, besides a backup, if no raid is underneath. (Triple). Obviously, you have all systems on UPS power......? I'd add any dirs with custom scripts and the kernel files also minimally replicated to another system. A comprehensive list of critical files is fine. Workstations and servers have different lists of critial files; and you can further subdivide the servers by function, to focus on those critical files and directories. So what is on the SSD that is important, just replicate it to a spinning HD on the local net. None of this replaces weekly backups, but give you a tertiary level of recovery redundancy for the important stuff. Triple redundancy is keenly important for all critical stuff; ymmv. Personally, I find max-ram and spinning HD to be the best bang for the buck. But, many folks with older portables are usually really happy with SSD as a replacement (single) drive that is cost effective but needs a network backup. [2] http://serverfault.com/questions/454775/is-post-sudden-power-loss-filesystem-corruption-on-an-ssd-drives-ext3-partition hth, James
