Milan Broz <mbroz@xxxxxxxxxx> on Fri, 15 Jul 2011 16:48:01 +0200: > On 07/15/2011 03:59 PM, Christian Hesse wrote: > > Ok, I do have a kernel with discard on dm-crypt support now. How do I > > set this option allow_discards for my device using dmsetup? dmsetup's > > manpage does not tell anything about it. > > Backup your data, really. Note there could be still bugs. I do have good backup. Really. ;) > You have to manually reload table with discard enabled for now, > it is quite complicated and dangerous because you will manipulate with > master key string directly: > > 1) Activate device using cryptsetup, remember active table for your device, > including key: > > # dmsetup table <your_device> --showkeys > > table will look like "0 1234 crypt aes-xts-plain64 <key> 0 8:2 8192" > (with different parameters according to your device, > do not forget --showkeys option) > > 2) Reload table with discard enabled, (add " 1 allow_discards" > to the end of table line) > > # dmsetup load <your_device> --"<line above> 1 allow_discards" > > 3) activate new table > > # dmsetup resume <your_device> > > (check that dmsetup table again - it should print discard support now) > > Alternatively, you can activate table directly (instead of cryptsetup) > > # dmsetup create <your_device> --table "<line above> 1 allow_discards") > > If you do not understand what are you doing here, please _wait_ until there > is official userspace support. > > Any mistake here will cause data corruption or complete data loss! If I understand correctly the table reload suspends my device? With the root partition inside the crypt device I would have to do this in initram disk I think... Perhaps I really should wait for support in cryptsetup. :D However... Thanks a lot for your work and the quick response! -- Schoene Gruesse Chris _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
