117-304 · Question #102
The xm list command has returned: Name ID Mem VCPUs State Time(s) Domain00 384 1 r 498.7 Debian 2 305 1 p 783.5 Slack 664 1 b 313.6 Centos 7 512 2 r 455.1 Which one of the following statements is…
The correct answer is E. Slack is idle or waiting for I/O. See the full explanation below for the reasoning.
Question
The xm list command has returned:
Name ID Mem VCPUs State Time(s) Domain00 384 1 r 498.7 Debian 2 305 1 p 783.5 Slack 664 1 b 313.6 Centos 7 512 2 r 455.1 Which one of the following statements is true about the above output?
Options
- AIt is necessary to use the xm command to change Slack's state to running.
- BCentos is the domain which has consumed the most CPU time.
- CThe domain with ID 2 uses paravirtualization.
- DBoth Debian and Slack require xm commands to start running.
- ESlack is idle or waiting for I/O.
How the community answered
(20 responses)- A10% (2)
- B5% (1)
- E85% (17)
Community Discussion
10
Toby R.Feb 13, 2026E is correct. The "b" state in xm list means "blocked," which is exactly what Xen calls a domain that is idle or waiting on I/O, so Slack fits that description perfectly, while the other options get tripped up by misreading the state codes or the Time(s) column.
Grace U.Jun 9, 2026E is your answer here, and it clicks once you know what the state letters mean: "b" stands for blocked, which in Xen means the domain is idle or waiting on I/O, not crashed or stuck. The other options fall apart fast if you check the state column, because "r" is running and "p" is paused, so Slack at "b" is the only one that matches the blocked/idle/waiting description.
Mateus R.Mar 2, 2026Think of process states like people in a waiting room at the DMV. "Blocked" is like someone who sat down because they called their number but the clerk is still processing paperwork for the person before them, so they are just sitting there waiting on something external before they can move forward. Given that, what do you think "blocked" actually means a domain is waiting on, and how does that connect to why E is correct rather than A?
Viktor S.Jun 21, 2026I was ready to mark C because paravirtualization is the whole point of Xen DomU guests and ID 2 fit neatly, but the question is asking what is true about THIS output, and the output gives you the state column right there. Slack's state is "b", which means blocked, and blocked in Xen means the domain is idle or waiting on I/O, so E is just reading the table correctly.
Anjali D.Jun 21, 2026Viktor nailed the read on "b" meaning blocked, though it is worth noting that blocked in Xen specifically covers both halted-idle and I/O-wait, so if the question tries to pin it to one of those you will want to check the answer choices carefully before committing.
Anjali D.Jun 19, 2026Okay so I kept reading option C over and over because ID 2 is the Debian domain and paravirtualization felt plausible there, but that is not actually something you can confirm from xm list output alone, so I had to let that go. What finally locked it in for me was going back to what the state codes actually mean. The "b" state stands for blocked, which in Xen means the domain is idle or waiting on I/O, not that it is stopped or needs a command to run. Slack has state "b" and that maps directly to option E. Option A tripped a few of us up because "blocked" sounds like it needs intervention, but blocked in this context is a normal runtime state, not a stuck or halted condition. Option D fell apart for the same reason, Debian is in state "r" which is running already, so that one cannot be right regardless. Anyone else initially second-guessed themselves on the blocked state definition? Would be curious whether the group leans the same way or if someone has a different read on C.
Grace U.Jun 21, 2026Your read on "b" is solid, and worth adding that blocked is actually the *expected* resting state for a well-behaved domain that is not burning CPU, so seeing it should be reassuring rather than alarming.
Lena V.Mar 15, 2026"b" state is blocked, meaning waiting on I/O, so E is correct, not "paused."
Wesley A.May 28, 2026C almost got me the first time because that "p" next to Debian screams paravirtualization until you remember it just means paused, and nothing in xm list output actually tells you the virtualization type. E is the one, blocked state means the domain is idle or waiting on I/O and will transition to running on its own without any xm intervention, which also kills D and A in one shot.
Grace U.May 30, 2026The E interpretation is solid, though it is worth adding that a domain stuck in blocked can sometimes mean it is waiting on a hung device backend, so it will not always self-resolve without some investigation on the dom0 side.