noonex's questions

I want to test disaster recovery of RDBMs after power loss under high load.

My idea is to mount data directory under new mountpoint and then execute umount -f during the load and investigate outcome / state of files.

My expectation is that with non-durable configuration the data should be inconsistent and consistent otherwise.

Does anybody think it is good idea and maybe other related hints (e.g. which filesystem better to use or my expectation is irrelevant, then why)?

I often need to create copy of files in varios locations(, and want to avoid excessive typing). (Then I will edit them)

Basically commands are like:

cp very/long/path/to/file/my-file_with-long.name very/long/path/to/file/my-file_with-long-another.name
vim very/long/path/to/file/my-file_with-long-another.name
cp even/longer/path/to/other/location/with_another-file_and-stupid.name even/longer/path/to/other/location/with_another-file_and-stupid-copy.name
vim even/longer/path/to/other/location/with_another-file_and-stupid-copy.name

I really want to avoid changing workdir with cd and typing the same path twice. Basically I can add command into bashrc like mydup, so it will create new file and return its name, so I cam use:

vim $(mydup very/long/path/to/file/my-file_with-long.name -another)
vim $(mydup even/longer/path/to/other/location/with_another-file_and-stupid.name -copy)

But maybe I invent bicycle and there is easier way to do the same?

Can somebody give me ideas about following situation (Linux 2.6.18-348.4.1.el5 ):

1. At some point tcpdump shows [FIN, ACK] packet sent from server port to local client
2. strace log shows no socket activity performed on that socket handle for that port near that moment (strace log properly shows the rest of communication for that client)
3. Firewall and SELinux are stopped
4. Problem is 100% reproducible with complex conditions which require the Server to perform network request for Kerberos authentication of another client connection.

What are potential causes which may lead tcpdump to show packet which missing in strace? Does it look more like server problem, TCP settings problem or some firewall service problem?

My application usually crashes and prints stack to log if received segfault signal.

But in some environment the 'dmesg' shows segfault messages related to my application, but application uptime is much older.

Can segfault be suppressed and application doesn't receive signal? Or what errors from dmesg can mean ?

Perhaps some server can handle both non-secure and secure protocols. Is there known way to determine if existing TCP connection secure or not?

(I believe it is possible just monitor traffic and check if some text is readable, but maybe there is better or maybe more detailed suggestions?)