On 09/20/2011 12:41:29 PM, Arno Wagner wrote: > On Tue, Sep 20, 2011 at 05:21:54PM +0200, Alexander Koch wrote: > > Am 20.09.2011 13:47, schrieb Arno Wagner: > > > With an SSD, things are a bit different. Due to the large > > > internal sector size, the header can be in a sector that > > > also has data that gets rewritten in it. As sectors are > > > always written completely, the header then is at risk whenever > > > that data gets rewritten. > No connection with TRIM support. It is just that if the real > block size is larger than the block size you are using, > the SSD will rewrite/reloacte other data on writes smaller > that the real sector size. > > What would need ot be done is to > 1. Align LUKS header (partition start) to a real sector > boundary. > 2. Align the start of the filesystem area in that > partition to a real sector boundary. > > Both are only possible to do realiably when you know the > sector size. All of my 3 SSDs claim 512 byte sectors, > which is almost certainly a lie. Performance is also going to suck if you don't get alignment right on drives with 4Kb sectors. FWIW here are the links I use to deal with 4Kb sector issues. http://ata.wiki.kernel.org/index.php/ATA_4_KiB_sector_issues http://lists.debian.org/debian-user/2011/01/msg02021.html Karl <kop@xxxxxxxx> Free Software: "You don't pay back, you pay forward." -- Robert A. Heinlein _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
