Re: Checksum mismatch in single repo

hello Daniel,

thank you for your quick answer, I reply inline:

On 27.10.23 08:23, Daniel Sahlberg wrote:
> Den fre 27 okt. 2023 kl 07:30 skrev Felix Natter 
> <[email protected]>:
>
>     Dear svn experts,
>
>     I do a daily dump+backup of my svn server. Without any known trigger
>     (no server crash, except about 2 months ago I had a single I/O
>     error on the
>     ProxMox virtualization server), the dump of one repo failed with:
>
>     svnadmin: E200046: LZ4 decompression failed
>
>     The svnadmin verify I ran to double check that also failed for
>     that one repo:
>
>     verifying /repos/X/Y...
>     * Error verifying repository metadata.
>     svnadmin: E160004: Checksum mismatch in item at offset 18983705 of
>     length 11921122 bytes in file /repos/X/Y/db/revs/0/221
>
>     After I restored X/Y from the last backup, and ran a
>     dump/backup/verify,
>     everything is fine for 4 days now.
>
> Good thing you did the dump/backup and verify steps!
>
> Do I understand the issue occurred about a week ago, you restored the 
> backup and now it has been working fine for the last 4 days? As 
> compared with the known I/O error 2 month ago (ie, a lot earlier)?

Yes, the I/O error occurred earlier and did not have consequences for 
"svnadmin dump/verify".

With the current (4 days ago) corruption, I did not see any I/O errors. 
SMART is also green
(please see below).

>     I couldn't find an error in the system logs (especially no I/O
>     errors).
>     The repos are on a HDD (in my experience they last longer than SSDs
>     with lots of write activity, i.e. daily dumps/backups/etc...).
>
>     Question: Can I rule out software failure?
>
> It is difficult to rule out, but there are not many reports of this 
> failure so I would guess it is more likely to be a corrupted bit of 
> data on your HDD.
Ok, thanks.
>
>     I am running svn 1.14.1
>     on ALMA Linux 8.x. Shall I install on a new HDD?
>
> You should probably check the SMART stats on the drive (on the 
> virtualisation host!) or any other indications you might have on an 
> upcoming failure to see if the HDD is indeed the issue.

I do not see a single problem in "smartctl -a /dev/sda" (I started a 
long test
with -t long earlier this week):

https://pastebin.com/7hi31CUg

But then I never identified a failing HDD using SMART...

Many Thanks and Best Regards,

Felix


>     No action needed?
>     Any other advice?
>
>     Many Thanks in Advance and Best Regards,
>     Felix
>
>
> Kind regards,
> Daniel Sahlberg
>
-- 

*SIDACT GmbH
Simulation Data Analysis and
Compression Technologies
*
*Felix Natter*
/Software Developer /

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Germany

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