Use different machines for linux arm64

[BrennanConroy]

Trying this out cc @dougbu

[dougbu]

If it works, please have a look @ the Disk utilization build step to see how funky that looks compared to other Linux jobs

[BrennanConroy]

Not sure what funky means for disk utilization. We knew that swtiching would increase the disk space. It seems the hosted agents use /dev/sda1 and the non-hosted use /dev/sdc1.

Before:

Filesystem      Size  Used Avail Use% Mounted on
udev            3.4G     0  3.4G   0% /dev
tmpfs           695M  8.9M  686M   2% /run
/dev/sda1        84G   81G  2.8G  97% /
tmpfs           3.4G  8.0K  3.4G   1% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           3.4G     0  3.4G   0% /sys/fs/cgroup
/dev/loop0       40M   40M     0 100% /snap/hub/43
/dev/loop1       94M   94M     0 100% /snap/core/8935
/dev/sda15      105M  3.6M  101M   4% /boot/efi
/dev/sdb1        14G   35M   13G   1% /mnt
/dev/loop2       94M   94M     0 100% /snap/core/9066

After:

Filesystem      Size  Used Avail Use% Mounted on
udev            7.9G     0  7.9G   0% /dev
tmpfs           1.6G  8.6M  1.6G   1% /run
/dev/sda1        30G  3.6G   26G  13% /
tmpfs           7.9G     0  7.9G   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs           7.9G     0  7.9G   0% /sys/fs/cgroup
/dev/sdc1       504G   26G  453G   6% /datadisks/disk1
/dev/sdb1        99G   60M   94G   1% /mnt

[dougbu]

"Funky" was about the utilization in the workspace. 8.9G isn't anywhere near the supposed 10G the hosted agents should provide. But, of course, we may create and delete files during a build; not easy to see our peak utilization.

[dougbu]

Also interesting to see the regular Alpine dockerbuild.sh job used 9.0G