If you run a Debian based distro (Ubuntu, Debian, Mint, MxLinux, Zorin, Julinux, etc) and would like to try 5.10, I have made .deb packages available in https://www.eskimo.com/kernel/linux-5.10-tickless/[client|server|/…deb

     Choose client if low latency is the most important thing, typically used in a workstation, gaming, or video production environment, and server if throughput is most important.  The client kernels are fully preemptive and have 1000Hz clock (but tickless), and the server kernels are non-preemptive with a 100Hz clock.

     Navigate to the appropriate directory then download all three “.deb” files and install with:

     dpkg -i *.deb

     I will be rebooting all the servers tonight starting around 11pm, should be concluded by midnight, to install a new kernel, 5.10.1.  Hopefully it will work and one boot will be enough.

     As with 5.9 which never really worked, there have been significant changes to NFS which we make heavy use of here.  If it works it will be a win because some of those changes will bring about better efficiency especially for sparse files which will help when moving virtual machines between physical hosts.  I’ve tested the NFS client and it seems to be working well but can’t really test servers adequately except with real traffic.

     Maintenance completed on vps2, vps3, and vps4.

   Now I will be taking vps1, mxlinux, and zorin down for about 1/2 hour each for imaging (a form of backup).

     I’m going to be taking vps2, vps3, and vps4 out of service for about 20-30 minutes each tonight for imaging (a form of backup in which the entire virtual machine image is copied).

     We have had a problem recently with dovecot corrupting it’s index files.  I do not know exactly when this started.  The version that Ubuntu provides is 2.3.11.

     I recently changed the mail client server from keeping things on an NFS mounted partition to local disk as the general consensus within the dovecot community seemed to suggest this was a NFS related problem.

     However, that did not resolve the issue.  Today I compiled the most recent version, 2.4-devel and installed it.  I also changed the locking from fcntl to dotlock which is slower but generally considered more reliable.

     Getting the mail server off of NFS did not stop it corrupting it’s dovecot-index files.  It is down presently as I’m trying to compile the current version to see if it is improved.

     My last attempt to change the way the mail system is organized failed because the kernel we were using had a bug that caused it to incorrectly read the partition tables.

     The kernel problem has been corrected.  I am going to take mail down for about an hour now to move to igloo and to attempt to change the way it is structured to get the spool off of NFS for the client server because dovecot used to provide imap and pop3 has some issues working properly in an NFS environment.

     During this time you will be able to read mail on shell servers but not via webmail, imap, or pop-3 and you will be unable to send mail.  This work should be completed by 10PM.

     What I’d hoped to do with mail didn’t work.  I’ve got to do a bit more research before making another attempt.

     We have had some issues with three different customers accessing e-mail.  I was unable to replicate this until tonight.  When it did fail for me the failures indicate an NFS problem with the new kernels, consequently on the NFS servers and mail clients I am going to revert to a previously known working kernel shortly.  This will, unfortunately, interrupt everyone’s session.

     One of our machines has a drive that is taking some errors.  It completely passes the SMART internal diagnostics but the errors indicate problems finding sector headers which can happen if a machine isn’t shutdown properly say during a power outage it can clobber some sector headers.

     While this can be fixed by a format, this drive is older than dirt (about eight years) so I’ve ordered a replacement.  I am expecting to take this machine down Halloween evening for drive replacement.  This is the only non-RAID drive on the machine but it’s used for booting.  If it fails no data will be lost but the machine will be unable to boot until we replace it.  I have a smaller drive which I could replace it with if the replacement does not arrive on time but I would rather replace it with a fresh drive and one with a larger cache should provide faster boot times.