Path: csiph.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Charles Lindsey Newsgroups: comp.os.linux.embedded Subject: Re: Time to abandon large mechanical hard drives? Date: Mon, 16 Jul 2018 11:20:16 +0100 Lines: 41 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=koi8-r; format=flowed Content-Transfer-Encoding: 7bit X-Trace: individual.net ymxAebsEkTmI5ABDMxjAWw1GXaiRNb1PEwY29qOXO1rkmAqs8= Cancel-Lock: sha1:DnvX+yBXpCMgRSs1cbPrtjLQyWM= User-Agent: Mozilla/5.0 (X11; Linux i686; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 In-Reply-To: Content-Language: en-GB Xref: csiph.com comp.os.linux.embedded:895 On 11/07/16 08:33, David Brown wrote: > On 08/07/16 15:29, Alexander Suvorov wrote: > That only applies to old, small or very low-end SSD's. If you have a > mid-range consumer SSD with 200GB+ of size, there is no realistic > workload that could ever come close to wearing it out. Well I have a box controlling the heating in our Church. Its SSD is actually a USB stick (about 10 years old now), but the stuff on it changes rarely (e.g. when I upgrade the software) and I carefully chose a web server (Appweb) that deliberately keeps its state information in RAM. So I hope the box will continue to run for many years (though things might break for other reasons in Jan. 2038). BUT there are a few kilobytes of data that are changing all the time (e.g. a record of temperature changes over the last month, and the schedule of upcoming heating requirements). I did not want to trust Flash memory for that, so I installed a 128 kB EEPROM (which claimed it could be overwritten a million times before wearing out). Was this a good move? Recently, I observed a lot of random read failures (which usually corrected themselves when you re-read the same address). Now it may be due to the hot weather (the room housing the box has regularly been at 30 degrees Celcius over this last month - maybe it will be OK when the weather gets cooler). Should I be worried? Data is written to it a byte at a time, whenever the temperature in one of the 4 zones changes by 0.1 degree. It is not clear whether, behind the scenes, it overwrites a full 12b-byte block when you try to overwrite a single byte. What alternative options do I have? -- Charles H. Lindsey ---------At my New Home, still doing my own thing----------- Tel: +44 161 488 1845 Web: http://www.cs.man.ac.uk/~chl Email: chl@clerew.man.ac.uk Snail: 40 SK8 5BF, U.K. PGP: 2C15F1A9 Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5