This post explains few quick linux commands to check server specifications. I tried to explain every command output in this post as follows:
# cat /sys/block/sda/queue/rotational 1
if above commnad returns 1 it means HDD else if it returns 0 then it is SSD.
# cat /proc/meminfo MemTotal: 131778740 kB
Above command returns huge list of outputs, however you can ignore all and should focus on 1st line which tells about total Memory. You can convert KBs to MBs at google in order to get values in MBs.