.pQd

New supermicro server does not ‘see’ some of NVMe drives

by .pQd
i got 3 identical new servers from supermicro – SYS-121C-TN10R. all three have the same disk setup – 2+4 NVMe drives, but Debian 12 just see 5 of them instead of 6. when i run dmesg on newly installed system i can see those errors: to solve it i had to change PCIe bifurcation in ... Read More

charging Amazfit Band 5

by .pQd
i’m a happy user of Amazfit Band 5. it’s dirt cheap, paired with gadgetbridge – works fine without sharing any data with cloud-hosted big brother, all in all – it helps to keep me moving around each day. i had few occasions when i needed to charge it [ every ~2 weeks ] and did ... Read More

Fastly returning “Requested host does not match any Subject Alternative Names (SANs) on TLS certificate”, HTTP/421

by .pQd
due to $reasons we have an nginx-proxy that is a reverse proxy forwarding to Fastly CDN which, in turn, forwards back to our infrastructure. starting from the 2024-02-27 this stopped working, for some HTTP queries. most notably those using OPTION verb. response that nginx was getting from Fastly had HTTP/421 status code and payload: colleague ... Read More

Ohook – activating MS office

by .pQd
this might be useful, especially for environments where automated tests of MS-office-dependent applications are done: https://massgrave.dev/ohook.html + https://github.com/asdcorp/ohook

parallel rsync

by .pQd
rsync remains my main tool for transferring backups or just moving data between servers. but it has some pain points – e.g. rsync’s checksum calculation or ssh over which data is piped can easily saturate single CPU core before i run out of storage I/O or network bandwidth. how to parallelize it – based on ... Read More

resources for learning SQL

by .pQd
SQL basics: indexes: https://use-the-index-luke.com/ ‘modern’ SQL: fiddles – web-based sandboxes:

bug in postgresql’s GIN index

by .pQd
it’s a story without happy end. i’m absolutely sure there’s an index-corruption bug in PostgreSQL 13; since i have not seen any mention of it being fixed – it’s likely in the following releases as well. i’ve tried to get attention to it on the pgsql-bugs mailing list but i failed. likely because i’ve never ... Read More

Apache2: url-based exception for ProxyPass

by .pQd
i have apache2 reverse proxy which passes traffic to some application server. everything going to /server/ is handled by http://localhost:8000. i had to do one exception – serve content for /server/something.txt from a static file. here’s what i did:

rsync to exfat mount

by .pQd
exfat does not carry information about user/group ownership of files/directories, has less precise timestamps. to make rsync stop complaining about it i’m using:

using clickhouse-local to analyze archived log files

by .pQd
at work we’re hoarding log files. it’s a low-cost, low-tech solution: btrfs, some python script archiving /var/log/*.log, *.1 from hundreds of servers. we have a peace of mind that whatever it is – as long as it’s logging to that folder – we’ll have an archive of it. till now, whenever there was a need ... Read More