4 ms·

Another Linux user data point: XPS13(9310)/512GB nvme/16GB RAM/2GB swapfile/kubuntu 20.10/kernel 5.11 (in use since ~Dec 5, 2020): SMART/Health Information (

Another Linux user data point: XPS13(9310)/512GB nvme/16GB RAM/2GB swapfile/kubuntu 20.10/kernel 5.11 (in use since ~Dec 5, 2020): SMART/Health Information (NVMe Log 0x02) Critical Warning: 0x00 Temperature: 33 Celsius Available Spare: 100% Available Spare Threshold: 50% Percentage Used: 0% Data Units Read: 631,319 [323 GB] Data Units Written: 1,157,883 [592 GB] Host Read Commands: 4,650,820 Host Write Commands: 7,329,774 Controller Busy Time: 16 Power Cycles: 37 Power On Hours: 45 Unsafe Shutdowns: 15 Media and Data Integrity Errors: 0 Error Information Log Entries: 1 Warning Comp. Temperature Time: 0 Critical Comp. Temperature Time: 0 I do Linux kernel dev and have done quite a few kernel compiles at this point (using Ubuntu's full config) as well as general browsing and some Docker workloads and Spotify... Judging by 'Power On Hours' combined with 'Data Units Written', looks like there's a bug to me. As a side, I don't know why 'Available Spare Threshold' is 50%, and the 1 'Error Information Log Entries' appears to be successful results of some test.

ryan29 6y ago
I have the same question here. How do you only have 45 power on hours in 80 days? Does anyone know why power on hours seem to be under reported so often?
- frant-hartm 6y ago
  Just a guess, but maybe it doesn't count time in low power modes?
- curryst 6y ago
  As it relates to the Mac's, I'm starting to wonder if their SMART reporting is just faulty. Power on Hours seems to be definitively wrong, I'm starting to wonder if all of the SMART data is bogus and there is no issue.
- the8472 6y ago
  On linux there are a bunch of "laptop mode" configurations that can minimize the time the disk will be woken up to actually write out data. The price is that you'll lose the last N minutes of work on a hard crash. And it only works when you have enough RAM to avoid swapping and keep dirty pages in memory. And your workloads don't explicitly call fsync. But if setup correctly your drive will spend most of its time sleeping.
  - Filligree 6y ago
    > And your workloads don't explicitly call fsync. If you run ZFS, you can set sync=disabled for your filesystems. This will disable fsync. Unlike most (all?) other filesystems, that's actually safe. ZFS doesn't reorder writes between transaction groups, so after a crash you'll get a consistent state from however many minutes ago. (However, txgs have a time limit of 5 seconds by default. You also need to increase that.)

ryan29 6y ago

I have the same question here. How do you only have 45 power on hours in 80 days? Does anyone know why power on hours seem to be under reported so often?

frant-hartm 6y ago
Just a guess, but maybe it doesn't count time in low power modes?
curryst 6y ago
As it relates to the Mac's, I'm starting to wonder if their SMART reporting is just faulty. Power on Hours seems to be definitively wrong, I'm starting to wonder if all of the SMART data is bogus and there is no issue.
the8472 6y ago
On linux there are a bunch of "laptop mode" configurations that can minimize the time the disk will be woken up to actually write out data. The price is that you'll lose the last N minutes of work on a hard crash. And it only works when you have enough RAM to avoid swapping and keep dirty pages in memory. And your workloads don't explicitly call fsync. But if setup correctly your drive will spend most of its time sleeping.
- Filligree 6y ago
  > And your workloads don't explicitly call fsync. If you run ZFS, you can set sync=disabled for your filesystems. This will disable fsync. Unlike most (all?) other filesystems, that's actually safe. ZFS doesn't reorder writes between transaction groups, so after a crash you'll get a consistent state from however many minutes ago. (However, txgs have a time limit of 5 seconds by default. You also need to increase that.)