thatcks

6 ms·

31.
by thatcks 9y ago
The various Illumos distributions routinely upstream their changes into the master Illumos repository ( https://github.com/illumos/illumos-gate ). I know that ZFS on Linux ( https://github.com/zfsonlinux&
32.
by thatcks 10y ago
Rules of thumb involving more swap than RAM probably date from decades ago, when Unix virtual memory systems were sufficiently primitive that the total amount of virtual memory you could use was just your swap space, not swap space plus (mo
33.
by thatcks 10y ago
Swap space is only partially related to virtual memory overcommit, and virtual memory overcommit is extremely common and almost unavoidable on most Unix machines. Part of this is a product of a deliberate trade-off in libraries between virt
34.
by thatcks 10y ago
What is wrong with the standard procedure is that once upon a time the standard procedure that everyone knew and coded to was steps 1 through 4, without step 5. Then Linux ext4 people decided that step 5 was necessary, or rather that they c
35.
by thatcks 11y ago
It's how the SSH protocol itself works. When the client connects to a server, it sends the (remote) username and then a series of public keys. If the server will accept the current public key, it asks the client to authenticate with th
36.
by thatcks 11y ago
Exposing shared public keys creates an information leak; it allows attackers to probe for valid and usable username/key combinations on your servers (and thereby discover valid usernames). This may be a trivial information leak or it m
37.
by thatcks 11y ago
A note: SIGHUP is far from obsolete in its original purpose. We may have stopped using modems but people still log in to Unix machines in ways that can get disconnected. If you SSH in to a machine and your SSH session is cut off by a networ
38.
by thatcks 14y ago
Our experience is that NFS works excellently in the environment it was designed for (a LAN environment of Unix machines administered by the same people). I still haven't seen a better Unix remote filesystem (and most of the modern distribut
39.
by thatcks 14y ago
In our case we run servers and then have thin desktops (using LTSP) that actually log in and run their sessions on the servers. The servers carry our entire password and group file because everyone can log in to them. In general, in any NFS
40.
by thatcks 14y ago
The problem (for large sites) is the CPU usage required to repeatedly re-parse and re-process the group file; this is apparently not insignificant for large group and password files. IO isn't an issue because as you note, it'll be cached.
41.
by thatcks 14y ago
I think there's been a misunderstanding. We (the people who ran into the accountsservice problem) don't have a Canonical support contract. hp50g, who commented upthread, is the one who had the Canonical support contract.
42.
by thatcks 14y ago
We did 'fix' these issues as soon as we managed to track down why the daemon was using up so much CPU time on our machines. I wrote my entry partly because I was annoyed at how terribly badly thought out the code was and partly to warn othe