Questions tagged [checksum]

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1answer
32 views

MX Linux ISO checksum mismatch

I went to the MX Linux website and their "Direct Download" linked me to their Sourceforge downloads page. I selected the first option - MX-19.2_September_x64.iso then checked the download ...
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1answer
18 views

Check installed packages + check effective deployement of packages [to detect problems caused by memory corruption]

My computer has a flawed memory stick for two years and I can't correct this (sticks aren't removable and computer cannot be changed : so it won't be the subject). Sometimes a content is corrupted ...
3
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1answer
79 views

sha1sum reports that checksums do not match even though they are identical

Perhaps I'm doing something very stupid here, but Google hasn't been very helpful in resolving the problem. I have an archive of files I made for backup purposes. I've generated an SHA1 checksum file ...
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0answers
17 views

how to check if someone override a directory?

Lets say i have an existing directory and someone did cp -r over this and some files changed. I want to detect this change. How can i do it ? I thought of using md5 or some checksum calculator for ...
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1answer
34 views

Can GNU tar incremental backup use checksums?

According to GNU tar manual: Incremental dumps depend crucially on time stamps, so the results are unreliable if you modify a file's time stamps during dumping (e.g., with the `--atime-preserve=...
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0answers
20 views

Is the output of `zfs send` deterministic?

My goal is to generate a single checksum for the entirety of a ZFS snapshot. If zfs send is deterministic (including across systems, meaning including on the system that receives the snapshot), then ...
0
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1answer
27 views

Checksum during rsync questions

Simple questions, I hope. if I'm running checksum (as a -c flag) on rsync, like so - rsync -c --log-file="/location/logfile.txt" \ -e "ssh -p {port number}" {source} {destination} will detected ...
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0answers
90 views

Checksum comparison file too large

I am trying to run a checksum comparison task on a large folder that I rsync from one Synology server to another. What I am trying to get is an output that shows me any differences between the ...
3
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0answers
38 views

A_Parity_Error_?

Now this is odd: While copying a tarred directory over my LAN using ssh from a Fedora machine to a FreeBSD machine. I get: Uncorrectable parity/CRC error (All the disks are set with S.M.A.R.T – ...
2
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1answer
74 views

Linux Live USB MD5 checksum integrity check failed for 5 files, are these files relevant?

When running manually the MD5 checksum integrity check from a USB Live Boot medium (Linux Mint 19), the command line shows "failed" for these 5 files: grub.cfg loopback.cfg chain.c32 isolinux.cfg ...
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0answers
7 views

Adding UDP checksum in IP layer after Xfrm transformation

I am doing a custom transformation of the packet using xfrm tables (IPv6). As part of the transformation, I am adding a UDP header (basically putting my data into an UDP a.k.a UDP encapsulation). The ...
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1answer
34 views

How to calculate the checksum of a file's name?

I tried with openssl as it is very fast: openssl sha1 "$(basename "very_big_image.png")" But this just substitutes the actual file for check summing.
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0answers
45 views

Why do we need filesystem block checksum?

Each sector on the disk has its own ECC to detect (and can sometimes correct) data corruption. Yet some filesystems like Btrfs and ZFS provide checksum for each of their data block. Is it really ...
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2answers
201 views

Count the sum of wc -l command output

i have a workspace tree like : /Directory /Dir1/file1, file2 /Dir2/file3, file4 /Dir3/file5, file6 ... I want to count the sum of the number of lines for each file in dir. I have this script,...
0
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1answer
68 views

Request file checksum from FTP server?

I am downloading some large files from a remote FTP server. Is it possible to request the server to send me checksums (e.g. sha256, or related variants) for the files in question?
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0answers
30 views

How can I validate the integrity of a torrent retrieved through DHT?

I've just downloaded a dataset made available through BitTorrent and (at length) transferred it to my home PC. Now I want to validate that nothing's been corrupted along the way. Unfortunately, the ...
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0answers
36 views

Need help to create a checksum file of a directory on linux

I backup my data to an external hard drive regularly, and in the past, some of the files ended up getting corrupted and I haven't noticed it until it was too late. So to prevent this, I would like to ...
4
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2answers
298 views

File Corruption between 2 HDD

I have a NAS running Ubuntu 16.04 LTS server i386 (kernel 4.4.211-0404211-generic). I use it with samba to share movies and music through my home network. I've tried to copy ~ 100 Go of data from an ...
2
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1answer
661 views

How to verify checksum file of centos 8?

How to verify that the CHECKSUM file for the CentOS 8 ISO is real? Download check sum and key: $ wget https://www.centos.org/keys/RPM-GPG-KEY-CentOS-Official $ wget http://www.gtlib.gatech.edu/pub/...
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0answers
36 views

Backups with checksums onto multiple drives

Is there a way to backup files onto multiple drives with checksums, which can be recovered without without manually having to see which files checksums are correct and copying the file from the drive ...
1
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2answers
139 views

unmount SD card makes file checksum change

I have an SD card mounted by Lubuntu at /media/$USERNAME/COREELEC/ I need to copy a file from one directory to another and rename it. However if I check the md5sum (or sha512sum) after I unmount it ...
2
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2answers
62 views

How to calculate n values in a column and the overall average?

I would really appreciate some help with this as I am relativity new to Linux. I'm using grep but I also want an average of all of my extracted values (irrespective of which column they are in) and ...
7
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1answer
228 views

Can files compressed with bzip2 be relied upon to be deterministic (reproducible)?

I am trying to determine if there are any potential issues using bzip2 to compress files that need to be 100% reproducible. Specifically: can metadata (name / inode, lastmod date, etc) or anything ...
4
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1answer
220 views

What checksum algorithm is used by Version 5 Unix?

I can't figure out, what algorithm was used in Unix V5 and V6 for the sum command. At first, I thought that it is a simple sum of bytes modulus 2^16. However for a string "1111111111\n" repeated 320 ...
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2answers
49 views

Keeping two offline data sets in sync

Suppose that we have two replicas A and B of a large data set in locations that don't have a good Internet connection. As a rule of thumb, let's say it's possible to transfer metadata but not actual ...
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1answer
865 views

How to disable TCP checksum validation on Linux?

For some reason, I want to disable TCP checksum validation on my Linux host. Is that possible to disable it?
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1answer
176 views

do I use sha256sum or sha256hmac for file checksum

I have a text file with stuff in it I want to checksum it and create a hash for later use to know if the file has changed, when used anywhere else which to use? sha256sum myfile or sha256hmac myfile
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1answer
169 views

EXT4 CRC32C checksum algorithms are badly documented

So I'm making some kind of research on EXT4 checksums. I found this page and tried to calculate checksum by myself. I've started with Superblock since it is sounds pretty simple: "The entire ...
1
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1answer
111 views

Can “parchive” be used for block devices?

As explained on wikipedia and Arch linux wiki "Parchive"s can be used to generate additional data for a file, that can be used in verification and even to some degree for repair/recovery of said file ...
2
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1answer
353 views

Use pv with find -exec

I use the following command to verify ~700 GiB of backed-up files: $ find -type f -exec md5sum {} + | sort > ~/checksums This takes many hours, so I would like to integrate pv into the command to ...
8
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4answers
3k views

Print SHA sums without “-” at the end?

Is it possible to have SHA sums print without the - appended to the end? $ echo test | sha1sum 4e1243bd22c66e76c2ba9eddc1f91394e57f9f83 - <--- this "-" dash/hyphen I know we can use awk and ...
4
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1answer
404 views

Is there a CLI utility to compute the same CRC as used in ZIP files?

# Create random file $ dd if=/dev/urandom /of=./test.dat bs=1K count=1 # Zip it $ zip test.zip test.dat # Dump contents for ZIP-computed CRC $ unzip -v test.zip Archive: test.zip Length ...
1
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1answer
914 views

What happened to elfsign and elfverify?

In "Uninformed Research -- informative information for the uninformed." 2003 mentions a tool called elfsign and elfverify. This is a tool to checksum and sign an ELF binary. I can't find that tool in ...
2
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1answer
547 views

Why does crc32 say some of my files are 'BAD'?

I used crc32 to compare some files with a backup of them. Out of 3556 files, 11 were reported as 'BAD' as in the following example: 9be46354 ./9836Feeding_the_dog_.mpeg BAD 9be46354 != ...
1
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3answers
72 views

Is it possible to search for a file using the checksum instead of the name? [duplicate]

Suppose I want to do a search to find out if I have a file that matches the sha256 generated from the file test1.txtusing the command: sha256sum -b test1.txt I get as output: ...
3
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5answers
8k views

How to verify a checksum using one command line?

Suppose I type and run the following command: sha256sum ubuntu-18.04.1-desktop-amd64.iso After a delay, this outputs the following: 5748706937539418ee5707bd538c4f5eabae485d17aa49fb13ce2c9b70532433 ...
1
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0answers
47 views

Is there a way to get package checksum using `zypper`?

How to get the checksum of the package when using zypper. I tried even the --xmlout option of zypper as zypper --xmlout --no-refresh install -D -y --no-recommends MozillaFirefox. Is there a way to ...
1
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1answer
849 views

Help with script/rsync command to move file with md5 sum comparison before deleting the source file/ [closed]

Referencing this post to find and delete duplicate files based on checksum, I would like to modify the approach to perform a copy operation followed by a file integrity check on the destination file. ...
1
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2answers
307 views

Fast way to get checksum for all files within a huge nested directory

We have a requirement to screen user-uploaded content. However, I've noticed that most of our user-uploaded content has actually originated from our own system: for example someone downloads a pdf ...
0
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1answer
807 views

md5sum warning about formatted lines

I am trying to validate a file using the following command: $ md5sum myfile_v2.1.ova -c myfile_v2.1.md5 md5sum: myfile_v2.1.ova: no properly formatted MD5 checksum lines found myfile_v2.1.ova: OK ...
4
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2answers
960 views

Easy backup solution to protect against bit rot (or verify)

I'm looking for an easy solution to protect against random bit flips (so-called bit rot) of data stored on various drives. They are not disk arrays, just single disks, that I backup once a week. So I'...
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0answers
238 views

compare checksum of files between two servers

I have to compare checksum of all files in /primary and /secondary folders in machineA with files in this folder /bat/snap/ which is in remote server machineB. The remote server will have lots of file ...
1
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1answer
3k views

compare checksum of files between two remote servers

On my local box "machineA", I have two folders "/primary" and "/secondary". These two folders have some files in it. Now on the remote server "machineB" I have one folder "/bat/snap/" which contains ...
1
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2answers
3k views

md5sum failed to open a file, directory issue

I'm having a problem checking certain .md5 files, they are all files that are in directories which have been renamed since the files were downloaded. [User1 Directory X]$ md5sum -c file1.txt.md5 ...
22
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2answers
2k views

md5sum prepends '\' to the checksum

Why md5sum is prepending "\" in front of the checksum when finding the checksum of a file with "\" in the name? $ md5sum /tmp/test\\test \d41d8cd98f00b204e9800998ecf8427e /tmp/test\\test The same ...
3
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0answers
405 views

Do rsync --checksum and diff usually have different outputs or is my hdd broken?

I set up a NanoPi Neo 2 with OpenMediaVault (Debian Jessie) as its OS and have an hdd attached to it (the OS is on an SD card). When I now copy my data from my external hard drive onto my system with ...
2
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2answers
964 views

csum errors on btrfs containing virtual disk

I have a btrfs disk that suffered some damage from hardware failure and spits i/o errors when copying certain files. I ran btrfs scrub, and when it reported csum errors I offlined it and did a btrfs ...
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1answer
943 views

How to verify file/directory integrity when using SCP over SSH?

I just copied a few directories and files using SCP from a SSH remote server. How can I check if the files were copied exactly and there were no errors or no files were skipped?
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2answers
1k views

How to separately checksum each “block” of a large file

I am storing some multi-GB files on two hard drives. After several years in offline storage (unfortunately in far from ideal conditions), I often get some files with bit-rot (the two copies differ), ...
3
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2answers
4k views

How to checksum a CD/DVD? (to verify integrity of my Debian installation)

So I'd like to checksum my Debian 9.0 installation DVD to be able to compare it to the respective .iso file's hashes and the published hashes to be able to verify my installation's integrity. I ...