### Author:  [@ajithpv](https://hub.mender.io/u/ajithpv)
#### Post date: [February 19, 2020, 7:47am UTC](https://hub.mender.io/t/solved-how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/1 "2020-02-19T07:47:16Z")
Hi,
I would like to modify one file (13MB file) of the rootfs (mender artifact) after the Yocto build.
The possible easy option is to use the provided `mender-artifact` tool to modify the file with `cp` command.
The above method is clear to me however, I’m confused with the manifest file.
Whether `mender-artifact` tool will automatically update the `manifest` with the updated SHA256 hash of the “`.ext4`”?
It is not clear for me from the [examples](https://docs.mender.io/2.0/artifacts/modifying-a-mender-artifact) that, what happens to the `manifest` once, we changed any rootfs file.
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### Author:  [@dellgreen](https://hub.mender.io/u/dellgreen)
#### Post date: [February 19, 2020, 8:06am UTC](https://hub.mender.io/t/solved-how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/2 "2020-02-19T08:06:59Z")
If using yocto, can you not use the rootfs post processing hooks to edit rootfs prior to the images being made?
ROOTFS\_POSTINSTALL\_COMMAND[¶](https://www.yoctoproject.org/docs/latest/ref-manual/ref-manual.html#var-ROOTFS_POSTINSTALL_COMMAND)
ROOTFS\_POSTPROCESS\_COMMAND[¶](https://www.yoctoproject.org/docs/latest/ref-manual/ref-manual.html#var-ROOTFS_POSTPROCESS_COMMAND)
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### Author:  [@ajithpv](https://hub.mender.io/u/ajithpv)
#### Post date: [February 19, 2020, 8:11am UTC](https://hub.mender.io/t/solved-how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/3 "2020-02-19T08:11:55Z")
Thank you @dellgreen for the suggestion.
Sorry for the confusion. My use case is different. The modification which I mentioned is not happening on the same build machine. It is happening on another machine where the file needs to be copied into the `.mender` artifact.
Hence, `mender-artifact` tools suits for my case.
Could you please let me know whether `mender-artifact` tool automatically take care of the `manifest` file present inside the `.mender` artifact?
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### Author:  [@mirzak](https://hub.mender.io/u/mirzak)
#### Post date: [February 19, 2020, 8:19am UTC](https://hub.mender.io/t/solved-how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/4 "2020-02-19T08:19:13Z")
> [@ajithpv](#):
>
> Could you please let me know whether `mender-artifact` tool automatically take care of the `manifest` file present inside the `.mender` artifact?
I would expect the tool to update the sha256 hash if you are using `mender-artifact cp`
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### Author:  [@ajithpv](https://hub.mender.io/u/ajithpv)
#### Post date: [February 19, 2020, 8:22am UTC](https://hub.mender.io/t/solved-how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/5 "2020-02-19T08:22:02Z")
Even I expect the same @mirzak.
I have tried to untar and checked the manifest before and after the update (with cp command). The rootfs sha256 hash is changing. However, I need a confirmation that our expection is correct 🙂
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### Author:  [@dellgreen](https://hub.mender.io/u/dellgreen)
#### Post date: [February 19, 2020, 8:56am UTC](https://hub.mender.io/t/solved-how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/6 "2020-02-19T08:56:30Z")
I would expect the hash to change and the new artifact to be resigned if you have supplied the key.
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### Author:  [@ajithpv](https://hub.mender.io/u/ajithpv)
#### Post date: [February 19, 2020, 9:15am UTC](https://hub.mender.io/t/solved-how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/7 "2020-02-19T09:15:36Z")
@dellgreen - Just to clarify, I have no signing in place. I’m just copy one file into the rootfs (.mender). However, the `.ext4` SHA256 hash will change as per my knowledge.
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### Author:  [@oleorhagen](https://hub.mender.io/u/oleorhagen)
#### Post date: [February 19, 2020, 10:08am UTC](https://hub.mender.io/t/solved-how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/8 "2020-02-19T10:08:16Z")
The manifest file should be recreated with the new sha.
Same goes for resigning.
If this does not work, I would call it a bug.
@ajithpv have you tried this and it fails? Or is this research simply?
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### Author:  [@ajithpv](https://hub.mender.io/u/ajithpv)
#### Post date: [February 19, 2020, 10:22am UTC](https://hub.mender.io/t/solved-how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/9 "2020-02-19T10:22:04Z")
@oleorhagen thank you for your confirmation.
I have tried and is working as I [mentioned](https://hub.mender.io/t/how-mender-artifact-will-work-with-the-manifest-rootfs-sha256-hash/1562/5) previously.
I need to submit this method to another team and hence I thought of asking and get confirmation from the experts 🙂
Thank you @mirzak , @dellgreen and @oleorhagen for your time 👍