Hello Microcal,
I use tmpfs heavily as I have an SSD.
Here are some information that can help you :
tank woody # mount -v | grep tmpfs
devtmpfs on /dev type devtmpfs
(rw,relatime,size=8050440k,nr_inodes=2012610,mode=755)
tmpfs on /run type tmpfs (rw,nosuid,nodev,relatime,size=1610408k,mode=755)
shm on /dev/shm type tmpfs (rw,nosuid,nodev,noexec,relatime)
cgroup_root on /sys/fs/cgroup type tmpfs
(rw,nosuid,nodev,noexec,relatime,size=10240k,mode=755)
tmpfs on /var/tmp/portage type tmpfs (rw,size=12G)
tmpfs on /usr/portage type tmpfs (rw,size=12G)
tmpfs on /usr/src type tmpfs (rw,size=12G)
tmpfs on /tmp type tmpfs (rw,size=12G)
tmpfs on /home/woody/.mutt/cache type tmpfs (rw)
tank woody # cat /etc/fstab
# /etc/fstab: static file system information.
#
# noatime turns off atimes for increased performance (atimes normally
aren't
# needed); notail increases performance of ReiserFS (at the expense of
storage
# efficiency). It's safe to drop the noatime options if you want and to
# switch between notail / tail freely.
#
# The root filesystem should have a pass number of either 0 or 1.
# All other filesystems should have a pass number of 0 or greater than 1.
#
# See the manpage fstab(5) for more information.
#
# <fs> <mountpoint> <type> <opts> <dump/pass>
# NOTE: If your BOOT partition is ReiserFS, add the notail option to opts.
/dev/sda1 / ext4 noatime,discard,user_xattr 0 1
/dev/sda3 /home ext4 noatime,discard,user_xattr 0 1
#/dev/sda6 /home ext3 noatime 0 1
#/dev/sda2 none swap sw 0 0
tmpfs /var/tmp/portage tmpfs size=12G 0 0
tmpfs /usr/portage tmpfs size=12G 0 0
tmpfs /usr/src tmpfs size=12G 0 0
tmpfs /tmp tmpfs size=12G 0 0
tmpfs /home/woody/.mutt/cache/ tmpfs size=12G 0 0
#/dev/cdrom /mnt/cdrom auto noauto,ro 0 0
#/dev/fd0 /mnt/floppy auto noauto 0 0
tank woody #
For the /usr/portage directory, if you reboot, all you have to do is
emerge-webrsync or do like me :
tank woody # l /usr/ | grep portage
924221 4 drwxr-xr-x 170 root root 4096 1 mars 02:51 portage_tmpfs
6771 0 drwxr-xr-x 171 root root 3500 11 juin 20:40 portage
tank woody #
The /usr/portage_tmpfs is a backup of the /usr/portage, this avoid me
retreiving all portage information from gentoo's servers.
Please note that I also use www-misc/profile-sync-daemon in order to
store my browsers cache on /tmp.
I rarely shutdown my computer :)
Have fun
On 19/06/2014 04:36, microcai wrote:
rsync is doing bunch of 4k ramdon IO when updateing portage tree,
that will kill SSDs with much higher Write Amplification Factror.
I have a 2year old SSDs that have reported Write Amplification Factor
of 26. I think the only reason is that I put portage tree on this SSD
to speed it up.
what is the suggest way to reduce Write Amplification of a portage sync ?
