SSD

Intro

Use preferably the ext4 file system (TRIM support). These following tips aims to extend the lifetime of a SSD.

Update to a newer Linux kernel

SSD caching is only supported on Linux 3.9 or newer. Debian Wheezy is shipped with Linux 3.2, but the 3.10 version is available in the backports:

aptitude install -t wheezy-backports linux-image-amd64

Mounting SSD filesystems

  • Add the noatime (or relatime) mount option in /etc/fstab, to disable (or significantly reduce) disk writes whenever a file is read, this improves filesystem read performance for both SSDs and HDDs.
  • If desirable, enable the discard filesystem options for automatic/online TRIM (the discard options is not needed if your SSD has enough overprovisioning (spare space) or you leave (unpartitioned) free space on the SSD):
    • Set discard mount option in /etc/fstab for the ext4 filesystem, swap partition, Btrfs, etc. See mount(8).
    • Set issue_discards option in /etc/lvm/lvm.conf for LVM. See lvm.conf(5).
    • Set discard option in /etc/crypttab for dm-crypt.

After changing filesystem options, update settings in all initramfs images:

update-initramfs -u -k all

Reduction of SSD write frequency via RAMDISK

  • Set RAMTMP, RAMRUN and RAMLOCK to yes (in /etc/default/rcS or /etc/default/tmpfs since Wheezy)

SWAP

Avoid to swap when the occupied memory exceeds 60% (default behaviour):

echo "vm.swappiness=0" >> /etc/sysctl.d/local.conf
sysctl -p /etc/sysctl.d/local.conf

Firefox

Open about:config, and add a string parameter named browser.cache.disk.parent_directory with the value /tmp.

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