Questions tagged [checksum]
The checksum tag has no usage guidance.
74
questions
39
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How to verify a file using an asc signature file?
As an example, this project offers an *.asc file with a PGP signature to verify the contents of the download (as opposed to a checksum, you can see the empty column): https://ossec.github.io/downloads....
- 503
34
votes
1
answer
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Too many incorrect checksum errors in TCPDUMP
I find too many incorrect checksum errors from a TCPDUMP done on a GNU Linux 64bit server. There are close to 50% incorrect chekcsums in the export?
cksum 0xe61f (incorrect (-> 0x8c37)
How can we ...
- 445
21
votes
4
answers
35k
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Creating a tar file with checksums included
Here's my problem : I need to archive to tar files a lot ( up to 60 TB) of big files (usually 30 to 40 GB each). I would like to make checksums ( md5, sha1, whatever) of these files before archiving; ...
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18
votes
4
answers
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How to get checksum data integrity on ext4?
On file systems like btrfs you can preform a scrub, which will go though all the data to see if the data still matches the file system checksum.
I would like to check the data on ext4 if it is ...
- 10.6k
8
votes
1
answer
3k
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ZFS vdevs accumulate checksum errors, but individual disks do not
I'm running a vendor-specific derivative of FreeNAS 9.3.
My trouble started when I installed a new JBOD chassis to add two new vdevs into my pool, and the chassis had a bad board. During this time, I ...
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7
votes
3
answers
14k
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Checksumming to verify rsync transfers
So rsync runs some checksums in the course of deciding what to transfer (i.e. what blocks within a file). But is there any reason to trust the file you end up with on the receive side any more than ...
- 263
6
votes
1
answer
4k
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Is it possible to access the ZFS checksums to compare files
I have a FreeNAS 8 machine (FreeBSD 8.2-RELEASE-p1) with two different shares on it. I'm migrating files from Share1 to Share2. The Shares have different directory structures and naming conventions. I'...
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6
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2
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2k
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zfs checksum error in raidz1 vdev but not in disk
I am backing up data stored in a zpool consisting of a single raidz vdev with 2 hard disks. During this operation, I got checksum errors, and now the status looks as follows:
pool: tmp_zpool
state:...
- 231
4
votes
1
answer
3k
views
Does NTFS / Windows as OS performs checksumming on file movement operations by default?
That's what I can't find
Does NTFS / Windows as OS performs checksumming on file movement operations by default?
alike ZFS or somehow else...
- 145
4
votes
1
answer
590
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What would cause a successful file transfer to have checksums not match? [closed]
After very large file transfers (this only happens with 10gig+ files) to a specific system, the receiving system would have a mismatched checksum of the file.
The transfer seems to have happened ...
- 41
4
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0
answers
2k
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btrfs, Force bad checksum recalculation
A large, USB-connected HDD with btrfs contains a 1TB file (a disk image). The first btrfs scrub after writing that file found 3 logical bad blocks developed somewhere in the middle of that file:
[ ...
- 767
3
votes
2
answers
9k
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SCP - Is a checksum required?
I'm backing up and transferring files automatically each night via scp.
I realize I get packet-level checksums via the protocol itself, but I'm wondering what the best practice is to ensure that a ...
- 585
3
votes
3
answers
17k
views
CentOS 6 on Hyper-V - network adapter doesn't work (no checksum feature)
I have installed CentOS 6.0 on Hyper-V Server 2008 R2 SP1. VM has only synthetic network adapter enabled. Installation was successfull (without any network), then I installed Linux Integration ...
- 113
3
votes
1
answer
546
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Why am I getting different SHA-1 checksums for tar of identical mongodump backups?
I am trying to backup my MongoDB database and check for changes with a SHA-1 checksum. The problem is that the checksum is not the same.
$ mongodump --quiet --db backup --out .
$ tar -cf backup1.tar ...
- 163
3
votes
4
answers
4k
views
Is there a generic filesystem checksum tool for Linux?
EDIT: clarify context
I have several loosely synchronized filesystems on different machines. (some content is redundant, some is not, things get moved by hand by the users). These are large ...
- 3,323
3
votes
2
answers
1k
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Checksumming mysql replicas over ssl
After hours of struggling to understand the way percona toolkits (2.1) pt-table-checksum works, I try to try you.
Situation
Running MySQL replication (Master-active:Master:passive)
Slave user is ...
- 31
3
votes
1
answer
3k
views
huge packet loss and checksum errors
Our 2008 server began to work very slowly within 2 weeks. Our web sites (iis 7.5) are loading very slowly and sometimes its freezing. We began testing with wireshark and saw that our packets are ...
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3
votes
2
answers
2k
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daily rsync backups with hard links, checksums, and a new computer
I backup my laptop to a Fedora desktop daily using rsync with hard links. This has worked great for almost a year.
I recently purchased a new computer, transferred over my data, and would like to ...
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3
votes
1
answer
228
views
Does ZFS, using default settings, use more physical space than ext4 for the same amount of data?
I'm currently considering a switch from ext4 to ZFS and am having trouble finding information about whether or not it uses more or less space to store the same amount of data as ext4. My understanding ...
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3
votes
1
answer
1k
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File corruption (bad checksums) in large files copied to VMware guest
In setting up a development lab, I've got a desktop system running ESXi 4.1.0 (free license) on SATA RAID 0 (already purchased and configured when I started this job; I'm open to hardware input as it ...
- 101
3
votes
0
answers
809
views
Get checksums of all packages on a yum repo server
I have a server I'm using as a yum reposerver. I've mirrored all the packages I want, and added additional packages in different folders. I've created multiple repos with the createrepo command. There ...
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3
votes
1
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316
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Is there any reference for current binary file checksums (Ubuntu 12.04 LTS)
I'm using rkhunter to check my system regularly - Sometimes rkhunter output some warnings on file changes (after update e.g.)
rkhunter gives me the new file checksum and the old one, but is there any ...
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2
votes
4
answers
4k
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Why is the TCP checksum inverted?
From the Wikipedia page:
The checksum field is the 16 bit one's complement of the one's complement sum of all 16-bit words in the header and text.
Why, after summing the 16-bits in the header and ...
- 1,175
2
votes
1
answer
2k
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Check all debian binaries against the checksum of the original
I would like to check all binaries on my server against
dpkg -e <path_to_deb_package> <destination>
(for example rkhunter could do this check against the originals when doing probupdate)...
- 2,517
2
votes
1
answer
800
views
Gzip command to produce exact same output than tar -cvzf?
I did thought the following commands where equivalent, but they produce different checksums:
tar -cvzf ... and tar -cvf ...; gzip ... does not produce the same output.
sha1sumdiffers.
What would be ...
- 415
2
votes
2
answers
1k
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Network boot (PXE) and caching of files
I'm looking into changing how to deploy network boot for
clusters of servers.
My worry is network transfer since not all boxes will be close
to boot servers and network might be slow.
The machines ...
- 123
2
votes
1
answer
5k
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gpg: no valid OpenPGP data found [closed]
I am trying to make sense of the following two serverfault posts:
How to verify a file using an asc signature file?
and
gpg --import bind-9.9.4.tar.gz.sha1.asc fails with no valid OpenPGP data ...
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2
votes
2
answers
7k
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Check if MySQL Replication is in sync
The MySQL documentation about CHECKSUM TABLE is very minimalistic.
My question: Is CHECKSUM TABLE a good way of checking if a MySQL Slave Table is in sync with the master? In other words: Can i use ...
- 23
2
votes
2
answers
233
views
How can I verify the integrity of a WAN connection?
We have two scanners in our branch office which upload images to the head office via FTP. In the last week, both scanners have started delivering a lot of corrupted images.
I suspect that the problem ...
- 13.6k
2
votes
2
answers
2k
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Why isn't TCP corruption more noticeable?
First of all, apologies if this seems a somewhat simplistic question.
According to this answer, TCP packets are corrupted all the time without the checksum catching it.
If this happens so often, ...
- 23
2
votes
1
answer
639
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Is it possible to disable zfs self-healing without disabling checksums?
I would like to disable ZFS self-healing in case of scenario as described here:
https://pthree.org/2013/12/10/zfs-administration-appendix-c-why-you-should-use-ecc-ram/
In that scenario bad RAM (ECC or ...
- 21
2
votes
2
answers
2k
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Windows checksums?
I am looking for a official source for windows checksums (in my special case windows xp). Normally I use the "Microsoft Benefit Portal" for that, but seems like it's gone, at least I can't find it ...
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2
votes
2
answers
3k
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How to enforce rsync against performing checksum?
We perform nightly backups of a Windows file server by first creating an incremental backup file on the server each night (as well as a complete backup on Thursday night), and then copying that to a ...
- 781
2
votes
1
answer
2k
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Does DisableTaskOffload disable all related LAN Adapter settings?
I have been getting problems disabling Checksum Offload in a lot of LAN adapters manually. Does setting the DisableTaskOffload value in the registry disable all of the related parameters regardless of ...
- 1,662
2
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0
answers
2k
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tcpdump: invalid cksum from client to localhost interface even after disabling offloading
I'm having a strange issue.
In linux I have two windows open. one running tcpdump and one running curl. I used curl to try to make a connection to local host and tcpdump logs invalid checksum errors. ...
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2
votes
0
answers
516
views
Disable or recalculate tcp checksum validation on `docker0` interface
Because I need to use esp in transport layer in a docker container, I want to disable tcp checksum verification in the docker container. Is there any way this is possible?
If not, is there some way I ...
1
vote
2
answers
5k
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Is the TCP checksum over the payload?
I was somehow convinced that the TCP checksum was a header checksum (similar to the IP checksum), but I'm now having doubts reading the Wikipedia article:
The checksum field is the 16 bit one's ...
- 1,175
1
vote
2
answers
1k
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sqlite.bz2 File does not match checksum - centos 5.7
I have tried absolutely everything, without good results...
yum always fails with "sqlite.bz2 File does not match checksum" for different repositories, every single time, but always with the above ...
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1
vote
2
answers
918
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Windows Equivalent to `sha256sum -c` (cryptographic hash, digest file, recursive integrity check, SHA256SUMS)
What is the equivalent to sha256sum -c in Windows?
I have a set of very important files that I need to copy-to and mirror across many different types of disks in many geographically distinct locations....
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1
vote
3
answers
2k
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Install Java EE 6 on CentOS 6
Having problems installing Java EE 6 in CentOS 6 x32.
I have removed all previous version of Java and freshly installed temporally jdk1.6.0_34.
So my $PATH variable goes to:
/usr/lib/qt-3.3/bin:/...
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1
vote
1
answer
456
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Rsync backups: checksums don’t match
I am a little confused by this although
diff –rq dir/ dir1/
does not show a difference
This rsync is to backup the directory
rsync -avrREz --delete --links -e "ssh -l user" --delete dir/ site....
- 4,443
1
vote
1
answer
164
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Windows 2003 Std server sending ip packets with checksum 0
So I was just doing some server side troubleshooting on the network I noticed that 1 of the servers sends all packets with the IP level checksum set to 0. It caught my eye because in my wireshark ...
- 280
1
vote
1
answer
138
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MediaWiki panic after modifying a file. Checksums maybe?
I've recently installed the latest version of MediaWiki on a dev server. I wanted to add some information on the edit page, and for this needed to modify an existing .php file to add in some more text....
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1
vote
0
answers
234
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Debian Bookworm Preseeding MD5 Checksum error
I have tried everything I can think of and different ways of calculating the MD5 but everytime the install comes back with Checksum does not match. Can anyone help me?
This is my txt.cfg. The checksum ...
- 11
1
vote
0
answers
531
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RPM --queryformat FILEMD5S checksum is different than md5sum of machine
The RPM man page says:
The FILEMD5S Tag The FILEMD5S tag is used to display the MD5 checksum
for each of the files that comprise the package.
Array: Yes (Size: One entry per filemd5s)
Used with ...
1
vote
0
answers
420
views
OSSEC Multiple "Integrity Checksum Changed" Alerts
I know this question has been asked several times, but the answers do not seem to work.
After installing OSSEC server on my Ubuntu Server 18.04 LTS machine, I've received hundreds of "Integrity ...
- 11
1
vote
0
answers
612
views
Suddenly cannot ssh into any machine
Suddenly I was not able to ssh to any machine. I thought it to be my router/network issue & I tried it with different network but the result was same. I took tcp dump on both server & client ...
- 11
1
vote
1
answer
778
views
ICMP/Internet checksum if packet entirely constists of zeros
We are currently investigating a strange behavior of different devices: if we send "empty" ICMP packets (that is, ICMP-SEQ and ICMP-ID are 0x0000 and no ICMP payload), for example using
nping --icmp ...
- 11
1
vote
0
answers
465
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How can I replicate Microsoft .NET manifest hashes, ideally on Linux command line?
I have a .NET click-once application which, I found out the hard way (user could not install), checks the checksums of its configuration files against checksums in the .exe.manifest as calculated at ...
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0
votes
1
answer
261
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how to properly compare the same two large files on two different servers byte for byte?
So I have two servers with the same 10gb gzip file on each.
On one server it unzips fine. On the other there are crc errors. The file sizes are the exact same.
the systems are exactly the same ...
- 129