On 26 May 2012 15:01, Wojciech Puchar <woj...@wojtek.tensor.gdynia.pl> wrote: >>> Why? Your laptop have most probably slow CPU and it will make everything >>> too slow if you make everything encrypted. >> >> >> I'd suggest some experiments - create a largish RAMdisk with and without >> GELI and see how the performance compares (this will be a lot faster than >> converting your SSD as well as saving a full-SSD erase/write cycle). > > > right. DO TESTs. > > mdconfig -a -t swap -s512m -u 0 > dd if=/dev/zero of=/dev/md0 bs=128k count=4k > dd if=/dev/md0 of=/dev/null bs=128k count=4k > > geli init -s 2048 /dev/md0 > geli attach /dev/md0 > dd if=/dev/md0.eli of=/dev/null bs=128k count=4k (*) > dd if=/dev/zero of=/dev/md0.eli bs=128k count=4k (*) > geli detach /dev/md0 > mdconfig -d -u 0 > > > but from my experience intel atom have very low geli performance, esp. older > models. and your laptop is atom based IMHO. > > result from commands marked with * on my atom based machine: > [root@bk ~/NOBACKUP]# dd if=/dev/md0.eli of=/dev/null bs=128k count=4k > 4095+1 records in > 4095+1 records out > 536868864 bytes transferred in 25.030418 secs (21448658 bytes/sec) > [root@bk ~/NOBACKUP]# dd if=/dev/zero of=/dev/md0.eli bs=128k count=4k > dd: /dev/md0.eli: short write on character device > dd: /dev/md0.eli: end of device > 4096+0 records in > 4095+1 records out > 536868864 bytes transferred in 26.050000 secs (20609169 bytes/sec) > > > as you can see results are awful, in spite it is > CPU: Intel(R) Atom(TM) CPU D525 @ 1.80GHz (1827.08-MHz K8-class CPU) > > And i actually do use geli on it, but as the only thing it does is regularly > running rsync to backup several other servers, it isn't a problem it can put > heavy CPU load. > > >> As for the overall SSD write rate, some time ago, I worked through >> minimising the write activity on the SSD in my laptop (I wrote a tool >> that monitors write transfers via devstat(3) and it would be possible >> to track down the actual modified files via kqueue(2) if necessary). >> I'm now down to about two chunks of about 13 transfers each per hour >> (due to entopy saving and ntp.drift updating). The changes were: >> 1) Mount the SSD filesystems as noatime > > > forgot about this. But this is good for ANY type of storage. > I run noatime everywhere and don't have problems. > > >> 2) Turn off all local syslogging (syslog is directed to another >> system when my laptop is at home, lost otherwise). > > > of course, or use /tmp/ for syslog. syslog is useful even on private > computer. > > >> 3) Change maillog rotation to size instead of daily > > > i - by default, and everywhere - turn off most things from default > /etc/crontab including rotation. > > and if you have syslog turned off or changed as i recommended you don't have > maillog file produced at all so no need to rotate. > > i recommend turning log rotation off at all everywhere, then turn it on > willingly based on actual needs. > > >> 4) Run save-entropy once per hour instead of roughly every 11 minutes. >> [Note that */11 means 0,11,22,33,44,55 not every 11 minute] >> 5) Patch the save-entropy script to reduce the write load when >> it's run (see PR bin/134225). >> 6) Use a swap-back /tmp > > use tmpfs and don't fear to add /var/tmp to it.
I would fear to add /var/tmp-- /var/tmp should persist across reboots. Chris _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"