Verifying Ubuntu ISO on MacBook Pro

I’m planning on switching to Ubuntu 18.04.2 on my MacBook Pro and I want to verify my download. I followed the steps from the Ubuntu tutorial and completed obtaining keys and getting a good signature, but then I got stuck on step which is to check ISO. Keep in mind I’m using the MacBook Pro terminal so maybe my function isn’t correct? On step 6, it tells me to type out

sha256sum -c SHA256SUMS 2>&1 | grep OK

so I can compare the verified checksum to the iso. Nothing really happens or I get some weird errors, I tried many variations such as using sha256sum on the iso and using that hash replacing “sha256sum” in the ubuntu tutorial etc.

However, if I just use sha256sum on the iso file itself, it’ll give me a hash. Then I use this hash and compare it to the SHA256SUMS file from ubuntu and it matches. So is it safe to say that I have a verified iso that ubuntu intended it to be?

Also, am I comparing what’s in the SHA256SUMS file or the hash of this function “sha256sum SHA256SUMS”. Sorry if my questions are everywhere as I am so new to this. Thanks!

Help choosing new monitor for my Mid 2012, 13-inch Macbook Pro Non Retina

I’ve been reading posts here and elsewhere for weeks but I’m trying to get input for my specific situation.

My Mid 2012, 13-inch MBP is usually always in clamshell mode hooked up to a decent 1080p 24″ display. I’m looking to upgrade my external monitor. I bought an LG 27″ 4K monitor (I knew I couldn’t run 4k, my MBP supports up to 2560×1600) but I thought of it as a future-proof buy for when I eventually upgrade my MBP. Through everything, I couldn’t get it to downscale to 2560×1440 without looking extremely small. Tried SwitchResX, alt when selecting scaled in display settings. Everything. I returned it.

I’m now looking to buy a 2560×1440 display in hopes it will scale better.

My questions are:

  1. Would it actually scale better/be useable on a 1440p monitor?

  2. 24″ or 27″ 1440p display?

  3. Any recommendations? My requirements are 2560×1440, DisplayPort, IPS panel and 24-27″.

Specs are as follows if that helps in any way:

MacBook Pro (13-inch, Mid 2012)

2.5 GHz Intel Core i5 8 GB 1067 MHz DDR3

Intel HD Graphics 4000 1536 MB

Any help is appreciated. Thanks in advance!

internal SSD crash. macbook retina early 2016. Mac OS X el capitan

My macbook crashed after an ongoing update. I get the “?” file when rebooting it. After several test i decided to reformat my SSD as it was impossible to install a new version of mac OS X on it. At this point, the SSD is crashing the reformat or erase process from diskutil. when i launched them. The system is starting to unmount the drive. Then freezing after 30 seconds approximately.

Here are the details of the hard drive and the errors diskutil view

the problem is disk0 diskutil general info

the gpt show command is showing this the gpt show command is showing this

when i try to repair the volume when i try to repair the volume

when i try to repair the disk when i try to repair the disk

Thanks a lot for the support Paul

macbook with lenovo c-dock duplicate external monitors

I connect my macbook to a lenovo c-dock, which connects 2 external monitors through 2 displayPort cables. The problem I have is that the 2 external moniotors mirror each other. I looked at the display settings, and there is no options to change it. How can I make the 2 exteranl monitors display differently?

I also tried to connect one of the monitor through VGA port, the 2 monitors still duplicate.

MacBook SSD failure after run xartutil –erase–all

MBP 2018(13-inch) got the Touch ID “reach fingerprint limit” problem, so I run xartutil –erase-all command in terminal recovery mode, then i cannot login to my account with correct password it seems that the command delete the decryption key to the hard drive, i tried to unlock it with diskutil but i failed with message “Error 69808 some information is unavailable during internal look up” is there any way that I can save my data? Thank you very much

Why, when my MacBook goes to sleep, does the WiFi stop working, unless I restart?

Is anyone else seeing this issue? If my MacBook goes to sleep and wakes up the WiFi simply will not work without a restart. I’m on macOS High Sierra 10.13.6.

I always test with the website cat.com since it tends to be fast. Nothing. Fast.com. Nothing. Restart, boom, everything works just fine.