Am Sonntag, 7. Februar 2016, 00:57:24 CET schrieb Matus UHLAR - fantomas: > On 06.02.16 19:30, Jos Collin wrote: > >I have Debian/testing installed completely in my 120GB SSD. I have > >learned that if an SSD fails, it is difficult to recover data from > >them. An SSD often does not give much warning before it fails. > >Electronic components don’t begin to grind or buzz as they grow > >older. They work – and then they don’t. > > > >So do I have to consider this risk and move the /home and /root > >directories to an HDD as they contain the Personal Data of each user, > >and only keep the Operating System files in the SSD ? How do you > >people keep the /home and /root directories, when you install the OS > >in an SSD ? (I have an Ultrabay Caddy, in which I can connect the HDD > >also in my Thinkpad T61). > > this is debian-laptop list, are you really talking about a laptop? > > I consider two possibilities for my home PC > 1. mirror SSD and HDD (I currently have two old 120 HDDs in mirror)
I think this can be done with regular rsync or btrfs send/receive. I probably wouldn´t try to use BTRFS RAID 1 or SoftRAID 1, cause I think the slower disk will slow down write accesses. Also I am not sure whether the RAID implementations are aware of disk speed and for example shuffle most of the reads to the SSD in that case. I bet they aren´t (yet). > 2. using bcache, dm-cache or flashcache (cache HDD on SSD) If you use bcache with write caching you basically double your risk of data loss. > maybe someone could share experience with some of these... bcache worked in a test more than a year ago I think. But I don´t use it, so… no idea about long term reliability. And alternative is also using a hybrid harddisk that uses a little amount of flash as caching. You have one device and its all transparent. But you have lots of logic in firmware. Seagate does these, I am not sure whether other vendors do these meanwhile as well. Personally I only stuff flash into laptops anymore cause laptop is just much more silent this way. I didn´t think back then that at one time I´d consider even a 2,5 inch harddisk as loud, but compared to the SSD – which can make some noices on heavy write accesses, at least my Intel SSD 320 does – they are. Thanks, -- Martin
