[tmpfs var/log] mount /var/log as tmpfs for some platforms (#2780)

SONiC is a heavy writer to /var/log partition, we noticed that this
behavior causes certain flash drive to become read-only over time.
To avoid this issue, we mount /var/log parition on these devices as
tmpfs.

- Mount /var/log as tmpfs
- /var/log default size is 128M
- Adjust size according to existing var-log.ext4 file size.
- Adjust size to between 5% to 10% of total memory size.

Signed-off-by: Ying Xie <ying.xie@microsoft.com>
This commit is contained in:
Ying Xie 2019-04-14 22:46:26 -07:00 committed by GitHub
parent 893837eca0
commit 8bf9247c5e
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@ -11,6 +11,31 @@ case $1 in
;; ;;
esac esac
set_tmpfs_log_partition_size()
{
varlogsize=128
# NOTE: certain platforms, when reaching initramfs stage, have a small
# limit of mounting tmpfs partition, potentially due to amount
# of RAM available in this stage. e.g. Arista 7050 QX32
[ X"$aboot_platform" = X"x86_64-arista_7050_qx32" ] && return
# set varlogsize to existing var-log.ext4 size
if [ -f ${rootmnt}/host/disk-img/var-log.ext4 ]; then
varlogsize=$(ls -l ${rootmnt}/host/disk-img/var-log.ext4 | awk '{print $5}')
varlogsize=$(($varlogsize/1024/1024))
fi
# make sure varlogsize is between 5% to 10% of total memory size
memkb=$(grep MemTotal /proc/meminfo | awk '{print $2}')
memmb=$(($memkb/1024))
minsize=$(($memmb*5/100))
maxsize=$(($memmb*10/100))
[ $minsize -ge $varlogsize ] && varlogsize=$minsize
[ $maxsize -le $varlogsize ] && varlogsize=$maxsize
}
## Mount the overlay file system: rw layer over squashfs ## Mount the overlay file system: rw layer over squashfs
image_dir=$(cat /proc/cmdline | sed -e 's/.*loop=\(\S*\)\/.*/\1/') image_dir=$(cat /proc/cmdline | sed -e 's/.*loop=\(\S*\)\/.*/\1/')
mkdir -p ${rootmnt}/host/$image_dir/rw mkdir -p ${rootmnt}/host/$image_dir/rw
@ -26,5 +51,16 @@ mount --bind ${rootmnt}/host/$image_dir/{{ DOCKERFS_DIR }} ${rootmnt}/var/lib/do
## Mount the boot directory in the raw partition, bypass the overlay ## Mount the boot directory in the raw partition, bypass the overlay
mkdir -p ${rootmnt}/boot mkdir -p ${rootmnt}/boot
mount --bind ${rootmnt}/host/$image_dir/boot ${rootmnt}/boot mount --bind ${rootmnt}/host/$image_dir/boot ${rootmnt}/boot
## Mount loop device for /var/log ## Mount loop device or tmpfs for /var/log
[ -f ${rootmnt}/host/disk-img/var-log.ext4 ] && mount -t ext4 -o loop,rw ${rootmnt}/host/disk-img/var-log.ext4 ${rootmnt}/var/log onie_platform=""
aboot_platform=""
. ${rootmnt}/host/machine.conf
if [ X"$aboot_platform" = X"x86_64-arista_7050_qx32" ] ||
[ X"$aboot_platform" = X"x86_64-arista_7050_qx32s" ]
then
set_tmpfs_log_partition_size
mount -t tmpfs -o rw,nosuid,nodev,size=${varlogsize}M tmpfs ${rootmnt}/var/log
[ -f ${rootmnt}/host/disk-img/var-log.ext4 ] && rm -rf ${rootmnt}/host/disk-img/var-log.ext4
else
[ -f ${rootmnt}/host/disk-img/var-log.ext4 ] && mount -t ext4 -o loop,rw ${rootmnt}/host/disk-img/var-log.ext4 ${rootmnt}/var/log
fi