sshd memory keeps increasing when client runs pscp - SSH

This is a discussion on sshd memory keeps increasing when client runs pscp - SSH ; [I posted this question to comp.unix.solaris with no answer yet. Reposted here] I run pscp (part of putty package) version 0.53b from Windows XP to copy close to 700MB files from Solaris 10 x86 with one single command. `df -k ...

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Thread: sshd memory keeps increasing when client runs pscp

  1. sshd memory keeps increasing when client runs pscp

    [I posted this question to comp.unix.solaris with no answer yet.
    Reposted here]

    I run pscp (part of putty package) version 0.53b from Windows XP to
    copy close to 700MB files from Solaris 10 x86 with one single command.
    `df -k /tmp` on server shows that available memory gradually goes down
    from the initial 688704 k to 0 and the server hangs (there're no files
    under /tmp). At this moment, pscp throws error "Fatal: Incorrect MAC
    received on packet". On the server, prstat shows that the number under
    sshd/1 SIZE keeps going up. The number I last see before server hang is

    665M (RSS is 6368K). Why does sshd use this much virtual memory, as if
    it wanted to cache all the files I transfer, and how do I prevent it?
    Thanks for help.

    Solaris version: 5.10 s10_63 i86pc i386 i86pc
    SSH version: SSH-2.0-Sun_SSH_1.1 (from telnet localhost 22;
    /etc/ssh/sshd_config has "Protocol 2"; `/usr/lib/ssh/sshd -ddd` shows
    "sshd version Sun_SSH_1.1")

    Yong Huang


  2. Re: sshd memory keeps increasing when client runs pscp

    yong321@yahoo.com writes:
    >I run pscp (part of putty package) version 0.53b from Windows XP


    I don't recommend doing that. 0.53b is a rather old version with a
    number of known serious security holes.
    I'd recommend running 0.57 at a minimum. (The latest version is 0.58,
    but you may need to apply a tweak to get it to run on XP; see the PuTTY
    website's front page for details.)

    (This has no bearing on your server problem, of course.)

  3. Re: sshd memory keeps increasing when client runs pscp

    On 2005-12-01, yong321@yahoo.com wrote:
    [about Sun_SSH_1.1]
    > 665M (RSS is 6368K). Why does sshd use this much virtual memory, as if
    > it wanted to cache all the files I transfer, and how do I prevent it?


    Sounds like a memory leak in sshd. Neither sshd nor scp should attempt
    to cache anything during copying.

    You can check if Sun has a patch for this, work around it by increasing
    the limits enough to allow it to complete (assuming you have enough
    swap spare) or try alternative SSH software.

    --
    Darren Tucker (dtucker at zip.com.au)
    GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4 37C9 C982 80C7 8FF4 FA69
    Good judgement comes with experience. Unfortunately, the experience
    usually comes from bad judgement.

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