upgrading firmware on Intel’s SATA SSD drives behind Dell’s h730p RAID

fetch Intel_SSD_Data_Center_Tool from here. the zip archive contained, among other, .deb for 64 bit OS – that worked for me under debian stretch. to see drives run: to upgrade the firmware where 0 corresponds to the Index of drive returned by the first command the same likely works for other LSI/Avago cards – no matter …

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openvpn – “OpenSSL: error:1408518A:SSL routines:ssl3_ctx_ctrl:dh key too small” after upgrade to Debina Buster

another thing to adjust after upgrade to Buster. on openvpn endpoint that in it’s config – /etc/openvpn/whatever.conf – had: dh dh1024.pem the vpn service did not start. tail -f /var/log/syslog showed: apparently the new version of openssl no longer accepts 1024 Diffie Hellman group. solution: and change in /etc/openvpn/whatever.conf – from dh dh1024.pem to dh …

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bind9 fails to start after an upgrade to Debian Buster

i’ve done a routine upgrade to Buster on some server and all went fine… except bind9 no longer started. every attempt to restart it ended up with long waiting and an error message: logs did not contain anything interesting – actually they showed that bind would start and then after ~ a minute was shut …

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allowing custom file extensions to be uploaded to wordpress

WordPress restricts types of files you can upload. it not only checks the extension of what you’re adding to the media library but also its mime type. so you cannot fool it by uploading .exe renamed to .jpeg – if you try it, you’ll get an error saying: “Sorry, this file type is not permitted …

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“error: internal error: unable to execute QEMU command ‘transaction’: Could not create file: Permission denied” when creating a snapshot under KVM

debian buster brings apparmor. apparmor brings problems – eg it’s too restrictive for libvirt KVM guests and does not allow KVM to create snapshot-related files in VM’s folders. so far i did not find a clean and generic way to address it so i had to disable apparmor for libvirt by adding security_driver = “none” …

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let’s encrypt via proxy server under debian

i prefer to have strict DROP policy for the outgoing traffic from production servers. let’s encrypt API endpoint is behind Akamai’s CDN and IP address to which acme-v02.api.letsencrypt.org resolves changes frequently. i don’t like playing whack-a-mole every 3 months so i’ve: set up a squid-based proxy server that allows for filtering based on domain names: …

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“Your IT department has turned off signup for Partner Center” when migrating to new Action Pack / Microsoft Partner Center

i got stuck on that one while trying to migrate action pack account to the new MS Partner Center. without the migration it would not let me renew. after 3 attempts i ended up talking with someone competent who found that this error might occur for users who have o365-hosted mails for domain used in …

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bridging lan segments across untrusted links

we’ve run out of the office space in one of the locations. in short term it was not possible to find a suitable and large enough place to rent so we had to split and relocate some of the staff to another building few kilometers away. it’s possible that we’ll shuffle people and servers between …

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multi-master mysql replication with servers on 3 different continents

at work i’m using mysql replication quite extensively. first it was a straightforward one-way replication that has been rock-solid for us since 2009. in 2012, for another type of data, we’ve started using master-master setup. initially the servers were in different European countries, eventually the secondary site was moved to North America while primary one …

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idrac upgrade failures

idrac gives you “RED006: Unable to download Update Package” and plenty of headaches during updates? it happened to me while jumping over few updates and going straight from 2.41.40.40 to 2.52.52.52. no amount of racadm racreset would help. upgrading first to 2.50.50.50 and only then to 2.52.52.52 did the trick for me.

Windows 10 client cannot anymore access public samba share that does not require any login

i’ve run into an issue where windows 10 desktop could not anymore access a simple samba share on a linux server; that linux server did not have any type of authorization put in place. Windows would randomly give errors ” might not have permission to use this network resource” or “Windows cannot access \\Server\ShareYou do …

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E5-2643 in r620 stuck at a very low cpu frequency

few weeks ago i’ve done a general firmware upgrade of 2 identical Dell Poweredge r620 servers. a while later i’ve noticed that one of them had really sluggish performances. i’ve noticed that /proc/cpuinfo has shown CPU frequencies of hundreds of MHz rather than thousands. cat /proc/cpuinfo |grep MHz gave me 16 rows of values between …

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lxc broken after upgrade from linux-image-4.12.0-0.bpo.1-amd64 to linux-image-4.13.0-0.bpo.1-amd64

lxc containers no longer start after i’ve upgraded debian stretch server from 4.12 kernel from stretch-backports repository to 4.13 also from backports. symptoms in /var/log/syslog: that was resolved by creating /etc/systemd/network/99-default.link with: via this comment. then there was nothing interesting in syslog but the lxc guest still would not start – lxc-start -F -n serverName …

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