Volkovoy is downright evil. He goes around whipping people, popping out from behind corners and scaring them, and enforcing stupid rules. Given that this book is set in a prison camp, you might expect Volkovoy to be one of many.
But he's actually the meanest guard we see by far. Most of the other guards are shown as not taking their jobs all that seriously, or as hating their jobs. The guards are also shown having a hard time controlling all the zeks. Overall, the guards as a group get fairly sympathetic treatment, even from Shukhov himself:
Then the shouts became less frequent: keeping tabs wasn't easy in that cutting wind. The guards weren't allowed to tie rags around their faces, mind. Theirs wasn't much of a job, either. (217)
Basically no one wants to be in the camp since it universally sucks for everyone. Unless you are a sadist like Volkovoy. Unlike the other guards we see, Volkovoy enjoys his job and is on a big power trip. He even scares the other guards.
Volkovoy was dreaded not just by the zeks and the warders but, so it was said, by the camp commandant himself. (173)
When he pops up, zeks are terrorized and the guards and warders work twice as hard to avoid pissing Volkovoy off. Volkovoy is responsible for getting Buynovsky tossed in the hole at the end of the day as well; he doesn't respond well to back-talk. Or to people standing, apparently.
Or else, when zeks were huddled outside [...] he would creep up and slash you across the neck [....] The crowd would reel back like an ebbing wave. The whipped man would clutch his burning neck, wipe the blood away, and say nothing: he didn't want a spell in the hole as well.
Just lately he'd stopped carrying his lash for some reason. (173)
It's no mistake that Volkovoy is the camp discipline officer. He's a downright nut about it. But the final line of that passage hints that Volkovoy's reign of terror might be lessening. It's very likely that he stopped carrying his whip because of the recent bout of throat cuttings in the camp. Even Volkovoy isn't immune to a threat like that, and the bulk of the camp probably wish they could kill him.