Chkdsk can take a long time if it detects a problem with its indexes although I never had one take 8 hours. Ten minutes or so is normally how long it takes with a corrupted index but if you have many errors much longer. I would suggest that you download and run the manufacture of your hard drive diagnostic software to check that your hard drive is ok.
Agreed it's finding corruption and with 177877 index entries getting moved/fixed etc that is probably why it took awhile, i'll also take forever if you have a large slower\older HDD.
I have a 120GB SSD for OS and It has to repair indexes constantly but I think it'll survive until I can get a larger/newer model, definitely check with SMART and whatever manufacturer tool your HDD has and you may be able to get a replacement if it isn't too old and has issues.
If it is a Seagate then they have a program where you pay $20 or so(less than) and they'll send you a new drive in advance so you can clone your current with seagate tools then send the old one back after(just make sure you do send it or you will get charged).
I've gotten drives replaced that way twice and it's really nice, torrenting can wreak havoc on drives due to the constant read/writes or so it seems to me anyway.