Bug#844987: lvm2: issue discards by default

[Heinrich Schuchardt]

Package: lvm2
Version: 2.02.167-1
Severity: wishlist

Dear Maintainer,

many devices use SSDs for these it makes senses to forward discard
issued by the file system to the device.

I suggest that in /etc/lvm/lvm.conf we set
issue_discards = 1.

If the file system issues discards and the hardware supports it
this setting will result in the forwarding of the discards to
the drive. This is what the user expects.

If the file system does not issue discards or the hardware does not
support it, this setting will have no effect.

There is no benefit for the average user to set
issue_discards = 0.

Best regards

Heinrich Schuchardt

-- System Information:
Debian Release: stretch/sid
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.7.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=de_DE.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) (ignored: LC_ALL set to en_US.UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages lvm2 depends on:
ii  dmeventd                  2:1.02.136-1
ii  dmsetup                   2:1.02.136-1
ii  init-system-helpers       1.46
ii  libblkid1                 2.29-1
ii  libc6                     2.24-5
ii  libdevmapper-event1.02.1  2:1.02.136-1
ii  libdevmapper1.02.1        2:1.02.136-1
ii  liblvm2app2.2             2.02.167-1
ii  libreadline5              5.2+dfsg-3+b1
ii  libudev1                  232-3
ii  lsb-base                  9.20161101

lvm2 recommends no packages.

Versions of packages lvm2 suggests:
pn  thin-provisioning-tools  <none>

-- Configuration Files:
/etc/lvm/lvm.conf changed [not included]

-- no debconf information