Category: 未分類

$ mount | grep \ /\
/dev/mapper/t430s--vg-root on / type btrfs (rw,noatime,nodiratime,ssd,discard,space_cache,subvolid=5,subvol=/)

       discard, nodiscard
           (default: off)

           Enable discarding of freed file blocks. This is useful for SSD devices, thinly provisioned LUNs, or virtual machine images; however, every storage layer must
           support discard for it to work. if the backing device does not support asynchronous queued TRIM, then this operation can severely degrade performance, because a
           synchronous TRIM operation will be attempted instead. Queued TRIM requires newer than SATA revision 3.1 chipsets and devices.

       If it is not necessary to immediately discard freed blocks, then the fstrim tool can be used to discard all free blocks in a batch. Scheduling a TRIM during a period
       of low system activity will prevent latent interference with the performance of other operations. Also, a device may ignore the TRIM command if the range is too
       small, so running a batch discard has a greater probability of actually discarding the blocks.

       If discarding is not necessary to be done at the block freeing time, there’s fstrim(8) tool that lets the filesystem discard all free blocks in a batch, possibly not
       much interfering with other operations. Also, the device may ignore the TRIM command if the range is too small, so running the batch discard can actually discard the
       blocks.

$ sudo smartctl --info /dev/sda | grep ^SATA
SATA Version is:  SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s)

$ time sudo mount -o remount,rw,noatime,nodiratime,ssd,nodiscard,compress=lzo,space_cache /
real    42m32.840s
user    0m0.014s
sys     0m15.209s
$ mount | grep \ /\
/dev/mapper/t430s--vg-root on / type btrfs (rw,noatime,nodiratime,compress=lzo,ssd,space_cache,subvolid=5,subvol=/)

 sudo git -C /etc diff HEAD^ -- /etc/fstab
diff --git a/fstab b/fstab
index b029749..386278f 100644
--- a/fstab
+++ b/fstab
@@ -5,7 +5,7 @@
 # that works even if disks are added and removed. See fstab(5).
 #
 # <file system> <mount point>   <type>  <options>       <dump>  <pass>
-/dev/mapper/t430s--vg-root /               btrfs   noatime,nodiratime,ssd,discard,space_cache 0       0
+/dev/mapper/t430s--vg-root /               btrfs   noatime,nodiratime,ssd,compress=lzo,space_cache 0       0
 # /boot was on /dev/sda2 during installation
 UUID=cba2591a-12da-481e-b239-c002faca22e1 /boot           ext2    defaults        0       2
 # /boot/efi was on /dev/sda1 during installation

$ dpkg-query -W btrfs-progs iotop smartmontools
btrfs-progs     5.2.1-1
iotop   0.6-24-g733f3f8-1
smartmontools   7.0-2
$ sudo smartctl -i /dev/sda | grep -E '^Device Model:|Firmware Version:|SATA Version is:'
Device Model:     Seagate BarraCuda SSD ZA1000CM10002
Firmware Version: STAS1024
SATA Version is:  SATA 3.2, 6.0 Gb/s (current: 6.0 Gb/s)
$ lsb_release -dr
Description:    Debian GNU/Linux bullseye/sid
Release:        unstable
$ uname -m
x86_64