tech

btrfs and nfs dont play nicely together

by .pQd
i use ghettoVCB to take backups of vmware esxi 6.5 vms. data is copied to a nfs share hosted on Debian Linux. for over a year i used btrfs partition as an underlying datastore for the nfs share. and i just could not get it to work for backups which size larger than available RAM ... Read More

ucarp and vmware esxi

by .pQd
i’ve moved a linux router from 9yo physical box to a vm running under esxi 6.5. it’s a designated master in pair of master / slave managed by ucarp. it took me a while to figure out why it was not working – why didn’t the slave ‘see’ the master machine? as it turned out ... Read More

bridge on vlans on active-backup bonding under debian stretch

by .pQd
i use this setup for few lxc servers. bonding provides me layer2 failover based on arp probes [ so it’ll work even if switch link stays up yet forwarding fails the mechanism will kick in ]. this is continuation of an earlier post, this time under debian stretch

“out of range” on drac console when booting debian stretch

by .pQd
i’ve installed debian stretch on an old dell poweredge 2950. after booting it i saw grub, few lines from kernel and then green screen with “out of range”: reboot, on the grub menu select “*Debian GNU/Linux”, press e, hilight a line with linux /boot/vmlinuz-4.9.0-3-amd64 root=/dev/sda1 ro quiet, add there vga=normal fb=false nomodeset and press ctrl+x ... Read More

sphinxsearch reborn as manticoresearch?

by .pQd
for the past year number of commits in my favorite open source text-search server – the sphinxsearch project – has dropped to nearly 0. looks like in the meanwhile some of the old contributors moved to another project – manticoresearch. the website of the new project features two prominent supporters – craigslist and boardreader. fingers ... Read More

unwanted wordpress trackback spam

by .pQd
today i’ve learned that disabling trackback in wordpress’s settings > discussion [ ] Allow link notifications from other blogs (pingbacks and trackbacks) on new articles is not enough. your old posts, created before the date when this check-box was un-ticked, will still allow trackback which might be spammy. solution? adjust the trackback setting on per-post ... Read More

varying svn checkout times under virtualized windows server 2016

by .pQd
we’ve set up a new build server using Windows Server 2016 running under ESXi 6.5. few days later devs came back with a complain: full svn checkout time varies a lot – it takes between 1 and 8 minutes. steps taken that hopefully resolved the issue: disable the icon cache of tortoise svn, then eventually ... Read More

bridging two physical interfaces of esxi server

by .pQd
my colleagues got into an unpleasant situation where one of two dedicated servers, running vmware esxi 6.0, rented from a datacenter lost its network connectivity. the datacenter/internet-facing interface is down, hours later, during regular working day, the hosting provider did not react and resolve the problem. maybe the network card died, maybe switch port misbehaves ... Read More

posting a file from command line with CURL

by .pQd
i needed to write a .bat script for windows to upload a log file. quick and nasty hack.. on the sending end: looks straightforward, worked when i tested; but failed to upload in the production setup. on the http server/PHP i was getting: turned out that the log file was growing. curl at the beginning ... Read More

extracting attachments from unix mail files

by .pQd
i log some of the messages passing by Postfix-based relay using always_bcc = bcc@somewhere.com in main.cf. Sometimes – to track spam or problems – i need to check content of the attachments. this comes handy if content is embedded inline i have to edit the file and replace or just add the 2nd part if ... Read More

dlink DXS-1210-12TC – web interface hanging

by .pQd
i’ve made a mistake again and bought a ‘cheap’, smart-managed network switch. dlink DXS-1210-12TC with 12 10gbase-t ports. and i got punished nearly immediately – the web interface of the device would hang on me after few days of uptime. sometimes it wasn’t even possible to log in, other times – i could log in ... Read More

drac5 / 6 with latest java 1.8.73

by .pQd
new java – new problems. “Error when reading form SSL socket connection” showed again after the upgrade to new java follow the steps from the earlier post and edit those in the C:\Program Files (x86)\Java\jre1.8.0_73\lib\security\java.security: also: go to the Control panel > java in the General tab: Settings > Delete files – mark all the ... Read More

Dell’s 10gbase-t network cards on Intel’s x540 chips

by .pQd
we’re upgrading few servers at work to have 10gbit/s connectivity. to keep things familiar i’ve decided to stick with [power hungry and latency-inducing] cat7 copper cabling and 10gbase-t. there are few dell poweredge r620 and r630 to be upgraded. currently those have proprietary broadcom-based daughter-cards with 4x 1000base-t ports. i preferred to replace them with ... Read More