user462982's questions

I just updated my proxmox server based on wheezy 7.1. to the latest version (3.1). It acts as a central mercurial repository that is accessed via ssh as well. It seems like I am unable to use ssh-hg since then.

The repository is hosted at /home/hg, access is restricted to the repository by a command prefix in ~/.ssh/authorized_keys: command="hg-ssh /home/hg/*" ssh-rsa AAAAB3NzaC1yc2EAXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX..."

My mercurial.ini:

[ui]
username = hg <[email protected]>
ssh = C:\PROGRA~1\TORTOI~1\TORTOI~2.EXE -ssh -2 -i C:\pathToHGCert\cert.ppk

This is what I get now on the server /var/log/auth.log when I try a pull from Mercurial Eclipse or TortoiseHG:

sshd[305458]: debug1: Forked child 305486.
sshd[305486]: Set /proc/self/oom_score_adj to 0
sshd[305486]: debug1: rexec start in 5 out 5 newsock 5 pipe 7 sock 8
sshd[305486]: debug1: inetd sockets after dupping: 3, 3
sshd[305486]: Connection from xx.xx.xx.xx port 51306
sshd[305486]: debug1: Client protocol version 2.0; client software version PuTTY_Local:_Feb__4_2012_13:00:34
sshd[305486]: debug1: no match: PuTTY_Local:_Feb__4_2012_13:00:34
sshd[305486]: debug1: Enabling compatibility mode for protocol 2.0
sshd[305486]: debug1: Local version string SSH-2.0-OpenSSH_6.0p1 Debian-4
sshd[305486]: debug1: permanently_set_uid: 103/65534 [preauth]
sshd[305486]: debug1: list_hostkey_types: ssh-rsa,ssh-dss [preauth]
sshd[305486]: debug1: SSH2_MSG_KEXINIT sent [preauth]
sshd[305486]: debug1: SSH2_MSG_KEXINIT received [preauth]
sshd[305486]: debug1: kex: client->server aes256-ctr hmac-sha1 none [preauth]
sshd[305486]: debug1: kex: server->client aes256-ctr hmac-sha1 none [preauth]
sshd[305486]: debug1: SSH2_MSG_KEX_DH_GEX_REQUEST_OLD received [preauth]
sshd[305486]: debug1: SSH2_MSG_KEX_DH_GEX_GROUP sent [preauth]
sshd[305486]: debug1: expecting SSH2_MSG_KEX_DH_GEX_INIT [preauth]
sshd[305486]: debug1: SSH2_MSG_KEX_DH_GEX_REPLY sent [preauth]
sshd[305486]: debug1: SSH2_MSG_NEWKEYS sent [preauth]
sshd[305486]: debug1: expecting SSH2_MSG_NEWKEYS [preauth]
sshd[305486]: debug1: SSH2_MSG_NEWKEYS received [preauth]
sshd[305486]: debug1: KEX done [preauth]
sshd[305486]: debug1: userauth-request for user hg service ssh-connection method none [preauth]
sshd[305486]: debug1: attempt 0 failures 0 [preauth]
sshd[305486]: debug1: PAM: initializing for "hg"
sshd[305486]: debug1: PAM: setting PAM_RHOST to "myProviderHostName"
sshd[305486]: debug1: PAM: setting PAM_TTY to "ssh"
sshd[305486]: debug1: userauth-request for user hg service ssh-connection method publickey [preauth]
sshd[305486]: debug1: attempt 1 failures 0 [preauth]
sshd[305486]: debug1: test whether pkalg/pkblob are acceptable [preauth]
sshd[305486]: debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
sshd[305486]: debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
sshd[305486]: debug1: temporarily_use_uid: 1002/1002 (e=0/0)
sshd[305486]: debug1: trying public key file /home/hg/.ssh/authorized_keys
sshd[305486]: debug1: fd 4 clearing O_NONBLOCK
sshd[305486]: debug1: matching key found: file /home/hg/.ssh/authorized_keys, line 2
sshd[305486]: Found matching RSA key: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx
sshd[305486]: debug1: restore_uid: 0/0
sshd[305486]: Postponed publickey for hg from xx.xx.xx.xx port 51306 ssh2 [preauth]
sshd[305486]: debug1: userauth-request for user hg service ssh-connection method publickey [preauth]
sshd[305486]: debug1: attempt 2 failures 0 [preauth]
sshd[305486]: debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
sshd[305486]: debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
sshd[305486]: debug1: temporarily_use_uid: 1002/1002 (e=0/0)
sshd[305486]: debug1: trying public key file /home/hg/.ssh/authorized_keys
sshd[305486]: debug1: fd 4 clearing O_NONBLOCK
sshd[305486]: debug1: matching key found: file /home/hg/.ssh/authorized_keys, line 2
sshd[305486]: Found matching RSA key: xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx
sshd[305486]: debug1: restore_uid: 0/0
sshd[305486]: debug1: ssh_rsa_verify: signature correct
sshd[305486]: debug1: do_pam_account: called
sshd[305486]: Accepted publickey for hg from xx.xx.xx.xx port 51306 ssh2
sshd[305486]: debug1: monitor_read_log: child log fd closed
sshd[305486]: debug1: monitor_child_preauth: hg has been authenticated by privileged process
sshd[305486]: debug1: PAM: establishing credentials
sshd[305486]: pam_unix(sshd:session): session opened for user hg by (uid=0)
sshd[305486]: User child is on pid 305509
sshd[305509]: debug1: SELinux support disabled
sshd[305509]: debug1: PAM: establishing credentials
sshd[305509]: debug1: permanently_set_uid: 1002/1002
sshd[305509]: debug1: Entering interactive session for SSH2.
sshd[305509]: debug1: server_init_dispatch_20
sshd[305509]: debug1: server_input_channel_open: ctype session rchan 256 win 16384 max 16384
sshd[305509]: debug1: input_session_request
sshd[305509]: debug1: channel 0: new [server-session]
sshd[305509]: debug1: session_new: session 0
sshd[305509]: debug1: session_open: channel 0
sshd[305509]: debug1: session_open: session 0: link with channel 0
sshd[305509]: debug1: server_input_channel_open: confirm session
sshd[305246]: debug1: server_input_channel_req: channel 0 request [email protected] reply 1
sshd[305246]: debug1: session_by_channel: session 0 channel 0
sshd[305246]: debug1: session_input_channel_req: session 0 req [email protected]
sshd[305509]: debug1: server_input_channel_req: channel 0 request exec reply 1
sshd[305509]: debug1: session_by_channel: session 0 channel 0
sshd[305509]: debug1: session_input_channel_req: session 0 req exec
sshd[305509]: debug1: Forced command (key option) 'hg-ssh /home/hg/*'
sshd[305509]: debug1: Received SIGCHLD.
sshd[305509]: debug1: session_by_pid: pid 305510
sshd[305509]: debug1: session_exit_message: session 0 channel 0 pid 305510
sshd[305509]: debug1: session_exit_message: release channel 0
sshd[305509]: debug1: session_by_channel: session 0 channel 0
sshd[305509]: debug1: session_close_by_channel: channel 0 child 0
sshd[305509]: debug1: session_close: session 0 pid 0
sshd[305509]: debug1: channel 0: free: server-session, nchannels 1
sshd[305509]: Connection closed by xx.xx.xx.xx
sshd[305509]: debug1: do_cleanup
sshd[305509]: Transferred: sent 3304, received 2512 bytes
sshd[305509]: Closing connection to xx.xx.xx.xx port 51306
sshd[305486]: debug1: PAM: cleanup
sshd[305486]: debug1: PAM: closing session
sshd[305486]: pam_unix(sshd:session): session closed for user hg
sshd[305486]: debug1: PAM: deleting credentials

Interestingly, I can login to the server with the same certficate using an unrestricted authorized_keys and Putty just fine.

Putty Version 0.62/0.63
TortoisePlink 0.61.0.9078 (ships with TortoiseHg 2.9, TortoiseHg 2.8.2, and probably before)

May it be that Wheezy introduced some changes that Putty can cope with whereas the out-dated TortoisePlink cannot?

I am doing large DB imports on a Postgres instance running in a Proxmox 1.9 OpenVZ virtualized Ubuntu 11.04. For some reason, the executable that initiates and controls the import (or Postgres), always stops at some point, typically, when there is high I/O load on the system (i.e. the proxmox host or in any of the VM instances) caused in addition to that of the importing process. I am trying to figure out the root issue and whether I can potentially avoid it. Ps tells me that wchan = n_tty_ for the importing process (which is sleeping). First of all what does this mean and what are good practices in how to debug further?

I am doing some IO intensive DB imports that run for several days now and the IO performance has dropped tremendously over times. The DB data files (log files) are on an ext4 formatted logical volume which is mounted with default options (did not specify something special in fstab). Since I just learned that ext4 enables write barriers by default: Q: Is there some way to disable write barriers online (i.e. while the file system is in use), because I cannot interrupt the import and don't want to restart it again. I am aware that

• write barriers might not be the only thing impeding performance
• it is a bad idea to have write barriers disabled on journalling file systems if data safty is important (e.g. on a production system)

Is there some program for windows that is able to do what dd does in linux out of the box? I need to copy from a file to a physical disk in raw mode where I need to define offsets for input and output. So for dd, I'd need to use the seek and skip parameters. I know there is (1) http://www.chrysocome.net/dd or I could try to (2) setup dd using cygwin but:

1. Does multiply the skip parameter with 512 (which I believe is wrong). I want to skip=4198399 sectors but it then tries to skip 2149580288 sectors (bs=512). So with this bug, the program is useless for me.

2. I tried to use dd under cygwin as partially decribed here: http://cygwin.com/ml/cygwin/2000-08/msg00885.html. I did this

   mount -f //./physicaldrive0 /dev/enc
   mount -f of=/dev/enc if=/cygdrive/f/inputfile.dat skip=4198399 seek=4209089
   

and got

dd: opening '/dev/enc': Invalid argument"

Similarily

    mount -f //./Device/Harddisk0/DR0 /dev/enc

resulted in

     dd: opening '/dev/enc': No such file or directory"

So I am tired of trying with cygwin.

Are there other programs/options that could accomplish a dd kind of raw copy (maybe some disk editor)?

Thanks