Add TRIM Support to PR4100

My Cloud OS 3 Personal & Network Attached Storage My Cloud Pro Series
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Add TRIM Support to PR4100.
I would like to add SSDs to PR4100 and cannot because TRIM is not supported.
Added 4 SA500 drives configured with RAID10 and TRIM is not supported and cannot be enabled because it does not exist in /etc/

/dev/sda4 on /mnt/HD_a4 type ext4 (rw,nosuid,nodev,noexec,noatime,nodiratime,nobarrier,quota,usrquota,grpquota,data=ordered)
/dev/sdb4 on /mnt/HD_b4 type ext4 (rw,nosuid,nodev,noexec,noatime,nodiratime,nobarrier,quota,usrquota,grpquota,data=ordered)
/dev/sdc4 on /mnt/HD_c4 type ext4 (rw,nosuid,nodev,noexec,noatime,nodiratime,nobarrier,quota,usrquota,grpquota,data=ordered)
/dev/sdd4 on /mnt/HD_d4 type ext4 (rw,nosuid,nodev,noexec,noatime,nodiratime,nobarrier,quota,usrquota,grpquota,data=ordered)
/dev/md1 on /mnt/HD/HD_a2 type ext4 (rw,noatime,nodiratime,nobarrier,quota,usrquota,grpquota,resgid=990,stripe=64,data=ordered)
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So, after a brief fiddling via ssh I found I can run busybox fstrim -v /mnt/HD/HD_a2/ and that trims all available space. (In my case it says 7928855695360 TRIMMED)