Every now and then you get an eye opener

This one is while we are conditioning a Forte NVMe unit, and I am running our OS install scripts. Running dstat in a window to watch the overall system … —-total-cpu-usage—- -dsk/total- -net/total- —paging– —system– usr sys idl wai hiq siq| read writ| recv send| in out | int csw 2 5 94 0 0 […]

new SIOS feature: compressed ram image for OS

Most people use squashfs which creates a read-only (immutable) boot environment. Nothing wrong with this, but this forces you to have an overlay file system if you want to write. Which complicates things … not to mention when you overwrite too much, and run out of available inodes on the overlayfs. Then your file system […]

there are times

that try my patience. Usually with poorly implemented filtering tools of one form or another. The SPF mechanism is to provide an anti-spoofing system, which identifies which machines are allowed to send email in your domain name. The tools that purport to test it? Not so good. I get conflicting answers from various tools for […]

Of course, this means more work ahead

Our client code that pulls configuration bits from a boot server works great. But the config it pulls is distribution specific. Where we need to be is distribution/OS agnostic, and set things in a document database. Let the client convert the configuration into something OS specific. This is, to a degree, a solved problem. Indeed, […]

Very preliminary RHEL7/CentOS7 SIOS base support

This is rebasing our SIOS tech atop RHEL7/CentOS7. Very early stage, pre-alpha, lots of debugger windows open … but … [root@usn-ramboot ~]# cat /etc/redhat-release CentOS Linux release 7.2.1511 (Core) [root@usn-ramboot ~]# uname -r 4.4.6.scalable [root@usn-ramboot ~]# df -h / Filesystem Size Used Avail Use% Mounted on tmpfs 8.0G 4.7G 3.4G 59% / Dracut is giving […]

When spam bots attack

I’ve been fixing up a few mail servers to be more discriminating over their connections. And I’ve noted that I didn’t have any automated tooling to block the spammers. I have lots of tooling to filter and control things. So I wrote a quick log -> ban list generator. Not perfect, but it seems to […]

Not-so-modern file system errors in modern file systems

On a system in heavy production use, using an underlying file system for metadata service, we see this: kernel: EXT4-fs warning: ext4_dx_add_entry:1992: Directory index full! Ok, where does this come from? Ext3 had a limit of 32000 directory entries per directory, unless you turned on the dir_index feature. Ext4 theoretically has no limit. Well, its […]