# Kernel crash kernel panic **URL:** \ **Category:** Support\ **Created:** [April 4, 2022, 12:16am UTC](https://discuss.pynq.io/t/kernel-crash-kernel-panic/3958 "2022-04-04T00:16:18Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![duaneellissd](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/duaneellissd/32/2976_2.png) [@duaneellissd](https://discuss.pynq.io/u/duaneellissd)\ **Post date:** [April 4, 2022, 12:16am UTC](https://discuss.pynq.io/t/kernel-crash-kernel-panic/3958/1 "2022-04-04T00:16:18Z")
> [@Kernel panic - PYNQ Z1](https://discuss.pynq.io/t/kernel-panic-pynq-z1/3581): > > I have a new PYNQ Z1 board. I tried to boot it with micro sd with the sd image of v2.7. But It gives the following error message. Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(176,2) The same issue occur when it tried with sd image v2.1 Any help on this matter is highly appriciated i have the exact same problem steps to repro duce: 1. download sdcard image from [pynq.io](http://pynq.io) site 2. unzip write to sdcard using dd if=filename.img of=/dev/sdb 3 insert card and power up using same card that came with pynq-z1 board ---
**Author:** ![stf](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/stf/32/2724_2.png) [@stf](https://discuss.pynq.io/u/stf)\ **Post date:** [April 4, 2022, 8:02am UTC](https://discuss.pynq.io/t/kernel-crash-kernel-panic/3958/2 "2022-04-04T08:02:44Z")
Hi there, Have you tried burning the image a few times and it is consistently happening, or have you only tried once? Have you tried using a different SD Card writer to burn the image? Do you have another SD Card that you can try? All the best, Shane ---
**Author:** ![duaneellissd](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/duaneellissd/32/2976_2.png) [@duaneellissd](https://discuss.pynq.io/u/duaneellissd)\ **Post date:** [April 4, 2022, 3:50pm UTC](https://discuss.pynq.io/t/kernel-crash-kernel-panic/3958/3 "2022-04-04T15:50:28Z")
Multipletimes. Two different cards I have only 1 sd card writer Also - understand that another person reported the exact same issue See: [Kernel panic - PYNQ Z1](https://discuss.pynq.io/t/kernel-panic-pynq-z1/3581) Thus - 2 independent cards, 2 independent(different) reader/writer hardware The other reporter states they used a windows tool to write I am using “dd if=img of=/dev/sdb” on my linux box UNKNOWN: if anything changed for the other reporter. If you think there is a problem with the procedure please give a complete Linux based procedure to replicate. If you think it is a hardware issue, explain where in the data chain the problem might have gone bad? I mean the USB has a crc16 on the data as it is transferred, the SDCARD uses a CRC16 on each of the 4 data lines when writing and when reading, - so unless the SDCARD CRC1 has failed something else is going on, I would like to know what you think would have failed? And - why do I not see any problems when writing a Raspberry PI sd card using the same SDCARD writer? (different card) One would think that if the reader/electronics is bad for card (A) it would also be bad for card(B) - or one would see random failures across both cards, both systems ---
**Author:** ![skalade](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/skalade/32/686_2.png) [@skalade](https://discuss.pynq.io/u/skalade)\ **Post date:** [April 4, 2022, 11:36pm UTC](https://discuss.pynq.io/t/kernel-crash-kernel-panic/3958/4 "2022-04-04T23:36:31Z")
What size is your sd card? Looking at the log from your [other post](https://discuss.pynq.io/t/kernel-panic/3956), these lines: ```auto mmcblk0: p2 size 15604212 extends beyond EOD, truncated No soundcards found. cfg80211: failed to load regulatory.db EXT4-fs (mmcblk0p2): bad geometry: block count 1950526 exceeds size of device (1932544 blocks) EXT4-fs (mmcblk0p2): bad geometry: block count 1950526 exceeds size of device (1932544 blocks) ``` seem to indicate you might be running out of memory on your rootfs partition. If that is the case I’d recommend trying a bigger sd card. Thanks Shawn ---
**Author:** ![duaneellissd](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/duaneellissd/32/2976_2.png) [@duaneellissd](https://discuss.pynq.io/u/duaneellissd)\ **Post date:** [April 5, 2022, 4:31am UTC](https://discuss.pynq.io/t/kernel-crash-kernel-panic/3958/5 "2022-04-05T04:31:04Z")
Ok - so the image is 7.6G - silly me - I thought that it would fit… on an 8GIG card! I have several 8 gig cards Bigger problem: The PYNQ-Z1 - _SHIPS_ with an 8gig card! This means the anyone who purchases a PYNQ-Z1 will hit this problem. And they will not know what the problem is ``` The users will assume the card that came with the Z1 is the correct card to use But - evidently it is not a viable card to use! ``` Perhaps you should inform DIGILENT that they need to swap out the SD CARD in all of their shipping product and change to a 16gig card I am sure the production stock (think: All the Z1 boards at Digikey, at Mouser, Element14, etc) - not to mention the Z2 boards and other boards - not sure if they ship with an SDCARD present or not! That entire distribution/supply pipe line is full of SD CARDS that will not work. This will cause no end of people grief and problems. I’ll go get a 32gig card, I have run into this problem before - you buy an SDCARD that is of size (X) - and in reality it is much smaller by some percentage and the image does not fit! The RASPBERRY PI group have a wonderful solution for this - the distribution SDCARD image they create is very tiny and only large enough to hold the files they require. This makes their SD CARD image UNIVERSAL! Step1 : the R-PI end-user(aka:victim) writes the SD Image to the SDCARD any SD CARD Step2 : insert and boot - you will notice there is a message about the SDCARD \* that is when the magic is happening! You should clone this magic! \* Step 3 : What is happening is the RPI examines the actual SD CARD then auto-expands the file system to fit the actual card in the machine Ask your self - do you really have 8GIG of stuff on that SDCARD image? Or - did you make the SDCARD this big so. you have plenty of room later? ---
**Author:** ![duaneellissd](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/duaneellissd/32/2976_2.png) [@duaneellissd](https://discuss.pynq.io/u/duaneellissd)\ **Post date:** [April 5, 2022, 4:34am UTC](https://discuss.pynq.io/t/kernel-crash-kernel-panic/3958/6 "2022-04-05T04:34:44Z")
Note: Why do I suggest _you_ contact Digilent and let them know what they ship will not work. If I was to do that and goto their Web Site and click on their “Support Link” for their product - it comes back to this site - so they do not support this product, they only build and ship the board I bet you have a better contact with them then I would have and probably would have better luck informing them of this issue (the card they include/ship with the product) no longer is functional and needs to be 16gig! ---
**Author:** ![skalade](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/skalade/32/686_2.png) [@skalade](https://discuss.pynq.io/u/skalade)\ **Post date:** [April 5, 2022, 9:13am UTC](https://discuss.pynq.io/t/kernel-crash-kernel-panic/3958/7 "2022-04-05T09:13:43Z")
Well as you might know PYNQ is a rolling project and with each new release the size of the sd card image can increase due to new feature additions/new packages/upgrades/etc. We are mindful of the 8GB threshold, but I suppose it is approaching, especially when these types of sd cards have a variance to them. The solution could be to reduce image size, but will have to look into it. Thanks Shawn ---
**Author:** ![duaneellissd](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.pynq.io/duaneellissd/32/2976_2.png) [@duaneellissd](https://discuss.pynq.io/u/duaneellissd)\ **Post date:** [April 7, 2022, 3:27am UTC](https://discuss.pynq.io/t/kernel-crash-kernel-panic/3958/8 "2022-04-07T03:27:05Z")
UPDATE \_ FIXED - I purchased a 10 pack of 32GIG microSD cards - these work great, the problem I had before has gone away. Thus I would suggest on your DOWNLOAD page - at least tell people to use 16gig cards (and specifically do not use 8gig cards) That alone would have stopped my problems in their tracks.