SyRenity's questions

I need to keep ProxyPass configurations in separate files due to deployment system we use in following form:

File 1:

<VirtualHost *:80>
    <Location /qa1/>
        ProxyPass http://localhost:8800/qa1/
        ProxyPassReverse http://localhost:8800/qa1/
        ProxyPassReverseCookiePath / /qa1/
    </Location>
</VirtualHost>

File 2:

<VirtualHost *:80>
    <Location /qa2/>
        ProxyPass http://localhost:8801/qa2/
        ProxyPassReverse http://localhost:8801/qa2/
        ProxyPassReverseCookiePath / /qa2/
    </Location>
</VirtualHost>

but Apache complains that: [warn] default VirtualHost overlap on port 80, the first has precedence

Any idea if/how it possible to have Apache merge the both configurations?

I have some open-source Xen images (.img), that I want to convert to VirtualBox.

Both the methods I tried (convertfromraw or to .xva via xva.py then to ova via XenConvert) produce FATAL: Fatal: No bootable medium found!.

Any idea what the most reliable method is for performing this conversion?

Thanks in advance.

We have a custom Yum repo that our developers upload builds to.

The problem is that after some time it becomes cluttered with old versions.

Removing the old versions manually is quite annoying, so before we try to automate it ourselves, I wonder if there any script that would clean old RPM's based on version (preferred) or time of upload.

Best would be if we could specify to simple save X last versions, and erase anything else. Then we could cron it and just let it run daily.

Thanks for any idea.

We are looking to switch to key-based management of SSH logins, and wonder if there any key-management systems which would allow us to centrally manage the access keys world-wide.

The system should ideally allow issuing key per client, and revoking them if needed, updating server machine keys on fly.

Does anyone know of such a system, either commercial or open source?

NOTE: To clarify, we need the key management for pretty large amount of cloud servers (EC2-like), and a small amount of service users. I guess LDAP + patch suggest below might be the way to go.

We are looking to purchase new 3 TB enterprise-grade drives and can buy either SAS or SATA models.

AFAIK, SAS generally gives better performance than SATA, but searching for benchmarks I found the article Seagate Constellation.2 and Constellation ES.2 Hard Drive Review .

The summary is that SATA was actually faster than SAS on most of tests. But reading through comments, it seems there is a feature called "prescan", which was apparently responsible for the low performance.

What can be recommended from a performance point of view, is it SATA or SAS? Is the real-world performance acceptable?

The kind of work-load of our systems is heavy multi-threaded sequential writing and erasing, with occasional random read access.

Can anyone advice for a production-level, open-source shared storage (SAN) file-system?

I read about GFS and GFS2, but the first one seems a bit outdated, and the second is not considered stable for production.

Are there others I can check into?

What are the main differences (other then UI) between RH/CentOS cluster and heartbeat?

I have some experience using heartbeat, but wondered what the RH/CentOS provides, and looking at docs it seems more or less the same, plus shared storage support (which can be done on heartbeat via GFS).

I have quite strange situation, where my CentOS 5.5 box loads are high, but the CPU and memory used are pretty low:

top - 20:41:38 up 42 days,  6:14,  2 users,  load average: 19.79, 21.25, 18.87
Tasks: 254 total,   1 running, 253 sleeping,   0 stopped,   0 zombie
Cpu(s):  3.8%us,  0.3%sy,  0.1%ni, 95.0%id,  0.6%wa,  0.0%hi,  0.1%si,  0.0%st
Mem:   4035284k total,  4008084k used,    27200k free,    38748k buffers
Swap:  4208928k total,   242576k used,  3966352k free,  1465008k cached

free -mt
             total       used       free     shared    buffers     cached
Mem:          3940       3910         29          0         37       1427
-/+ buffers/cache:       2445       1495
Swap:         4110        236       3873
Total:        8050       4147       3903

Iostat also shows good results:

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           3.83    0.13    0.41    0.58    0.00   95.05

Here is the ps aux output:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0  10348    80 ?        Ss    2010   2:11 init [3]                                           
root         2  0.0  0.0      0     0 ?        S<    2010   0:00 [migration/0]
root         3  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/0]
root         4  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/0]
root         5  0.0  0.0      0     0 ?        S<    2010   0:02 [migration/1]
root         6  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/1]
root         7  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/1]
root         8  0.0  0.0      0     0 ?        S<    2010   0:02 [migration/2]
root         9  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/2]
root        10  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/2]
root        11  0.0  0.0      0     0 ?        S<    2010   0:02 [migration/3]
root        12  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/3]
root        13  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/3]
root        14  0.0  0.0      0     0 ?        S<    2010   0:03 [migration/4]
root        15  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/4]
root        16  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/4]
root        17  0.0  0.0      0     0 ?        S<    2010   0:01 [migration/5]
root        18  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/5]
root        19  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/5]
root        20  0.0  0.0      0     0 ?        S<    2010   0:11 [migration/6]
root        21  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/6]
root        22  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/6]
root        23  0.0  0.0      0     0 ?        S<    2010   0:01 [migration/7]
root        24  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/7]
root        25  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/7]
root        26  0.0  0.0      0     0 ?        S<    2010   0:00 [migration/8]
root        27  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/8]
root        28  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/8]
root        29  0.0  0.0      0     0 ?        S<    2010   0:00 [migration/9]
root        30  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/9]
root        31  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/9]
root        32  0.0  0.0      0     0 ?        S<    2010   0:08 [migration/10]
root        33  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/10]
root        34  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/10]
root        35  0.0  0.0      0     0 ?        S<    2010   0:05 [migration/11]
root        36  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/11]
root        37  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/11]
root        38  0.0  0.0      0     0 ?        S<    2010   0:02 [migration/12]
root        39  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/12]
root        40  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/12]
root        41  0.0  0.0      0     0 ?        S<    2010   0:14 [migration/13]
root        42  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/13]
root        43  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/13]
root        44  0.0  0.0      0     0 ?        S<    2010   0:04 [migration/14]
root        45  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/14]
root        46  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/14]
root        47  0.0  0.0      0     0 ?        S<    2010   0:01 [migration/15]
root        48  0.0  0.0      0     0 ?        SN    2010   0:00 [ksoftirqd/15]
root        49  0.0  0.0      0     0 ?        S<    2010   0:00 [watchdog/15]
root        50  0.0  0.0      0     0 ?        S<    2010   0:00 [events/0]
root        51  0.0  0.0      0     0 ?        S<    2010   0:00 [events/1]
root        52  0.0  0.0      0     0 ?        S<    2010   0:00 [events/2]
root        53  0.0  0.0      0     0 ?        S<    2010   0:00 [events/3]
root        54  0.0  0.0      0     0 ?        S<    2010   0:00 [events/4]
root        55  0.0  0.0      0     0 ?        S<    2010   0:00 [events/5]
root        56  0.0  0.0      0     0 ?        S<    2010   0:00 [events/6]
root        57  0.0  0.0      0     0 ?        S<    2010   0:00 [events/7]
root        58  0.0  0.0      0     0 ?        S<    2010   0:00 [events/8]
root        59  0.0  0.0      0     0 ?        S<    2010   0:00 [events/9]
root        60  0.0  0.0      0     0 ?        S<    2010   0:00 [events/10]
root        61  0.0  0.0      0     0 ?        S<    2010   0:00 [events/11]
root        62  0.0  0.0      0     0 ?        S<    2010   0:00 [events/12]
root        63  0.0  0.0      0     0 ?        S<    2010   0:00 [events/13]
root        64  0.0  0.0      0     0 ?        S<    2010   0:00 [events/14]
root        65  0.0  0.0      0     0 ?        S<    2010   0:00 [events/15]
root        66  0.0  0.0      0     0 ?        S<    2010   0:00 [khelper]
root       107  0.0  0.0      0     0 ?        S<    2010   0:00 [kthread]
root       126  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/0]
root       127  0.0  0.0      0     0 ?        S<    2010   0:03 [kblockd/1]
root       128  0.0  0.0      0     0 ?        S<    2010   0:01 [kblockd/2]
root       129  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/3]
root       130  0.0  0.0      0     0 ?        S<    2010   0:05 [kblockd/4]
root       131  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/5]
root       132  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/6]
root       133  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/7]
root       134  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/8]
root       135  0.0  0.0      0     0 ?        S<    2010   0:02 [kblockd/9]
root       136  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/10]
root       137  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/11]
root       138  0.0  0.0      0     0 ?        S<    2010   0:04 [kblockd/12]
root       139  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/13]
root       140  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/14]
root       141  0.0  0.0      0     0 ?        S<    2010   0:00 [kblockd/15]
root       142  0.0  0.0      0     0 ?        S<    2010   0:00 [kacpid]
root       281  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/0]
root       282  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/1]
root       283  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/2]
root       284  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/3]
root       285  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/4]
root       286  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/5]
root       287  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/6]
root       288  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/7]
root       289  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/8]
root       290  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/9]
root       291  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/10]
root       292  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/11]
root       293  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/12]
root       294  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/13]
root       295  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/14]
root       296  0.0  0.0      0     0 ?        S<    2010   0:00 [cqueue/15]
root       299  0.0  0.0      0     0 ?        S<    2010   0:00 [khubd]
root       301  0.0  0.0      0     0 ?        S<    2010   0:00 [kseriod]
root       490  0.0  0.0      0     0 ?        S     2010   0:00 [khungtaskd]
root       493  0.1  0.0      0     0 ?        S<    2010  94:48 [kswapd1]
root       494  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/0]
root       495  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/1]
root       496  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/2]
root       497  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/3]
root       498  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/4]
root       499  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/5]
root       500  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/6]
root       501  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/7]
root       502  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/8]
root       503  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/9]
root       504  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/10]
root       505  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/11]
root       506  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/12]
root       507  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/13]
root       508  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/14]
root       509  0.0  0.0      0     0 ?        S<    2010   0:00 [aio/15]
root       665  0.0  0.0      0     0 ?        S<    2010   0:00 [kpsmoused]
root       808  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/0]
root       809  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/1]
root       810  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/2]
root       811  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/3]
root       812  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/4]
root       813  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/5]
root       814  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/6]
root       815  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/7]
root       816  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/8]
root       817  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/9]
root       818  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/10]
root       819  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/11]
root       820  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/12]
root       821  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/13]
root       822  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/14]
root       823  0.0  0.0      0     0 ?        S<    2010   0:00 [ata/15]
root       824  0.0  0.0      0     0 ?        S<    2010   0:00 [ata_aux]
root       842  0.0  0.0      0     0 ?        S<    2010   0:00 [scsi_eh_0]
root       843  0.0  0.0      0     0 ?        S<    2010   0:00 [scsi_eh_1]
root       844  0.0  0.0      0     0 ?        S<    2010   0:00 [scsi_eh_2]
root       845  0.0  0.0      0     0 ?        S<    2010   0:00 [scsi_eh_3]
root       846  0.0  0.0      0     0 ?        S<    2010   0:00 [scsi_eh_4]
root       847  0.0  0.0      0     0 ?        S<    2010   0:00 [scsi_eh_5]
root       882  0.0  0.0      0     0 ?        S<    2010   0:00 [kstriped]
root       951  0.0  0.0      0     0 ?        S<    2010   4:24 [kjournald]
root       976  0.0  0.0      0     0 ?        S<    2010   0:00 [kauditd]
postfix    990  0.0  0.0  54208  2284 ?        S    21:19   0:00 pickup -l -t fifo -u
root      1013  0.0  0.0  12676     8 ?        S<s   2010   0:00 /sbin/udevd -d
root      1326  0.0  0.0  90900  3400 ?        Ss   14:53   0:00 sshd: root@notty 
root      1410  0.0  0.0  53972  2108 ?        Ss   14:53   0:00 /usr/libexec/openssh/sftp-server
root      2690  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/0]
root      2691  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/1]
root      2692  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/2]
root      2693  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/3]
root      2694  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/4]
root      2695  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/5]
root      2696  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/6]
root      2697  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/7]
root      2698  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/8]
root      2699  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/9]
root      2700  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/10]
root      2701  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/11]
root      2702  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/12]
root      2703  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/13]
root      2704  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/14]
root      2705  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpathd/15]
root      2706  0.0  0.0      0     0 ?        S<    2010   0:00 [kmpath_handlerd]
root      2755  0.0  0.0      0     0 ?        S<    2010   4:35 [kjournald]
root      2757  0.0  0.0      0     0 ?        S<    2010   3:38 [kjournald]
root      2759  0.0  0.0      0     0 ?        S<    2010   4:10 [kjournald]
root      2761  0.0  0.0      0     0 ?        S<    2010   4:26 [kjournald]
root      2763  0.0  0.0      0     0 ?        S<    2010   3:15 [kjournald]
root      2765  0.0  0.0      0     0 ?        S<    2010   3:04 [kjournald]
root      2767  0.0  0.0      0     0 ?        S<    2010   3:02 [kjournald]
root      2769  0.0  0.0      0     0 ?        S<    2010   2:58 [kjournald]
root      2771  0.0  0.0      0     0 ?        S<    2010   0:00 [kjournald]
root      3340  0.0  0.0   5908   356 ?        Ss    2010   2:48 syslogd -m 0
root      3343  0.0  0.0   3804   212 ?        Ss    2010   0:03 klogd -x
root      3430  0.0  0.0      0     0 ?        S<    2010   0:50 [kondemand/0]
root      3431  0.0  0.0      0     0 ?        S<    2010   0:54 [kondemand/1]
root      3432  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/2]
root      3433  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/3]
root      3434  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/4]
root      3435  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/5]
root      3436  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/6]
root      3437  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/7]
root      3438  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/8]
root      3439  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/9]
root      3440  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/10]
root      3441  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/11]
root      3442  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/12]
root      3443  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/13]
root      3444  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/14]
root      3445  0.0  0.0      0     0 ?        S<    2010   0:00 [kondemand/15]
root      3461  0.0  0.0  10760   284 ?        Ss    2010   3:44 irqbalance
rpc       3481  0.0  0.0   8052     4 ?        Ss    2010   0:00 portmap
root      3526  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/0]
root      3527  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/1]
root      3528  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/2]
root      3529  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/3]
root      3530  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/4]
root      3531  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/5]
root      3532  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/6]
root      3533  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/7]
root      3534  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/8]
root      3535  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/9]
root      3536  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/10]
root      3537  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/11]
root      3538  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/12]
root      3539  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/13]
root      3540  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/14]
root      3541  0.0  0.0      0     0 ?        S<    2010   0:00 [rpciod/15]
root      3563  0.0  0.0  10160     8 ?        Ss    2010   0:00 rpc.statd
root      3595  0.0  0.0  55180     4 ?        Ss    2010   0:00 rpc.idmapd
dbus      3618  0.0  0.0  21256    28 ?        Ss    2010   0:00 dbus-daemon --system
root      3649  0.2  0.4 563084 18796 ?        S<sl  2010 179:03 mfsmount /mnt/mfs -o rw,mfsmaster=web1.ovs.local
root      3702  0.0  0.0   3800     8 ?        Ss    2010   0:00 /usr/sbin/acpid
68        3715  0.0  0.0  31312   816 ?        Ss    2010   3:14 hald
root      3716  0.0  0.0  21692    28 ?        S     2010   0:00 hald-runner
68        3726  0.0  0.0  12324     8 ?        S     2010   0:00 hald-addon-acpi: listening on acpid socket /var/run/acpid.socket
68        3730  0.0  0.0  12324     8 ?        S     2010   0:00 hald-addon-keyboard: listening on /dev/input/event0
root      3773  0.0  0.0  62608   332 ?        Ss    2010   0:00 /usr/sbin/sshd
ganglia   3786  0.0  0.0  24704   988 ?        Ss    2010  14:26 /usr/sbin/gmond
root      3843  0.0  0.0  54144   300 ?        Ss    2010   1:49 /usr/libexec/postfix/master
postfix   3855  0.0  0.0  54860  1060 ?        S     2010   0:22 qmgr -l -t fifo -u
root      3877  0.0  0.0  74828   708 ?        Ss    2010   1:15 crond
root      3891  1.4  1.9 326960 77704 ?        S<l   2010 896:59 mfschunkserver
root      4122  0.0  0.0  18732   176 ?        Ss    2010   0:10 /usr/sbin/atd
root      4193  0.0  0.8 129180 35984 ?        Ssl   2010  11:04 /usr/bin/ruby /usr/sbin/puppetd
root      4223  0.0  0.0  18416   172 ?        S     2010   0:10 /usr/sbin/smartd -q never
root      4227  0.0  0.0   3792     8 tty1     Ss+   2010   0:00 /sbin/mingetty tty1
root      4230  0.0  0.0   3792     8 tty2     Ss+   2010   0:00 /sbin/mingetty tty2
root      4231  0.0  0.0   3792     8 tty3     Ss+   2010   0:00 /sbin/mingetty tty3
root      4233  0.0  0.0   3792     8 tty4     Ss+   2010   0:00 /sbin/mingetty tty4
root      4234  0.0  0.0   3792     8 tty5     Ss+   2010   0:00 /sbin/mingetty tty5
root      4236  0.0  0.0   3792     8 tty6     Ss+   2010   0:00 /sbin/mingetty tty6
root      5596  0.0  0.0  19368    20 ?        Ss    2010   0:00 DarwinStreamingServer
qtss      5597  0.8  0.9 166572 37408 ?        Sl    2010 523:02 DarwinStreamingServer
root      8714  0.0  0.0      0     0 ?        S    Jan31   0:33 [pdflush]
root      9914  0.0  0.0  65612   968 pts/1    R+   21:49   0:00 ps aux
root     10765  0.0  0.0  76792  1080 ?        Ss   Jan24   0:58 SCREEN
root     10766  0.0  0.0  66212   872 pts/3    Ss   Jan24   0:00 /bin/bash
root     11833  0.0  0.0  63852  1060 pts/3    S+   17:17   0:00 /bin/sh ./launch.sh
root     11834  437 42.9 4126884 1733348 pts/3 Sl+  17:17 1190:50 /usr/bin/java -Xms128m -Xmx512m -XX:+UseConcMarkSweepGC -jar /JavaCore/JavaCore.jar
root     13127  4.7  1.1 110564 46876 ?        Ssl  17:18  12:55 /JavaCore/fetcher.bin
root     19392  0.0  0.0  90108  3336 ?        Rs   20:35   0:00 sshd: root@pts/1 
root     19401  0.0  0.0  66216  1640 pts/1    Ss   20:35   0:00 -bash
root     20567  0.0  0.0  90108   412 ?        Ss   Jan16   1:58 sshd: root@pts/0 
root     20569  0.0  0.0  66084   912 pts/0    Ss   Jan16   0:00 -bash
root     21053  0.0  0.0  63856    28 ?        S    Jan30   0:00 /bin/sh /usr/bin/WowzaMediaServerd /usr/local/WowzaMediaServer/bin/setenv.sh /var/run/WowzaM
root     21054  2.9 10.3 2252652 418468 ?      Sl   Jan30 314:25 java -Xmx1200M -server -Djava.net.preferIPv4Stack=true -Dcom.sun.management.jmxremote=true -
root     21915  0.0  0.0      0     0 ?        S    Feb01   0:00 [pdflush]
root     29996  0.0  0.0  76524  1004 pts/0    S+   14:41   0:00 screen -x

sar -W output:

12:00:01 AM  pswpin/s pswpout/s
12:10:01 AM      0.00      0.00
12:20:01 AM      0.00      0.00
12:30:02 AM      0.00      0.00
12:40:01 AM      0.00      0.00
12:50:01 AM      0.00      0.00
01:00:01 AM      0.00      0.00
01:10:01 AM      0.00      0.00
01:20:01 AM      0.00      0.00
01:30:01 AM      0.00      0.00
01:40:01 AM      0.00      0.00
01:50:01 AM      0.00      0.00
02:00:02 AM      0.00      0.00
02:10:01 AM      0.07      0.00
02:20:01 AM      0.00      0.00
02:30:02 AM      0.00      0.00
02:40:01 AM      0.00      0.00
02:50:01 AM      0.00      0.00
03:00:01 AM      0.00      0.00
03:10:01 AM      0.00      0.00
03:20:01 AM      0.00      0.00
03:30:01 AM      0.00      0.00
03:40:02 AM      0.00      0.00
03:50:01 AM      0.00      0.00
04:00:01 AM      0.00      0.00
04:10:01 AM      0.00      0.00
04:20:02 AM      0.01      0.00
04:30:01 AM      0.00      0.00
04:40:02 AM      0.11      0.00
04:50:01 AM      0.01      0.00
05:00:02 AM      0.03      0.00
05:10:01 AM      0.00      0.00
05:20:02 AM      0.01      0.00
05:30:01 AM      0.04      0.00
05:40:02 AM      0.08      0.00
05:50:01 AM      0.00      0.00
06:00:02 AM      0.11      0.00
06:10:01 AM      0.01      0.00
06:20:01 AM      0.00      0.00
06:30:02 AM      0.00      0.00
06:40:01 AM      0.05      0.00
06:50:02 AM      0.00      0.00
07:00:02 AM      0.01      0.00
07:10:01 AM      0.02      0.00
07:20:02 AM      0.00      0.00
07:30:01 AM      0.00      0.00
07:40:02 AM      0.17      0.00
07:50:01 AM      0.11      0.00
08:00:02 AM      0.00      0.00
08:10:01 AM      0.04      0.00
08:20:02 AM      0.00      0.00
08:30:01 AM      0.00      0.00
08:40:02 AM      0.03      0.00
08:50:01 AM      0.00      0.00
09:00:02 AM      0.08      0.00
09:10:01 AM      0.00      0.00
Average:         0.02      0.00

sar -d 5 0 output

09:18:40 AM       DEV       tps  rd_sec/s  wr_sec/s  avgrq-sz  avgqu-sz     await     svctm     %util
09:18:45 AM    dev8-0     21.96     11.18   2128.54     97.45      0.62     20.33      1.75      3.85
09:18:45 AM    dev8-1      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
09:18:45 AM    dev8-2     18.16      0.00    507.78     27.96      0.39     21.42      1.09      1.98
09:18:45 AM    dev8-3      3.79     11.18   1620.76    430.32      0.23     15.11      4.95      1.88
09:18:45 AM    dev8-4      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
09:18:45 AM    dev8-5      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
09:18:45 AM   dev8-16     19.36      0.00    619.56     32.00      0.35     18.22      0.94      1.82
09:18:45 AM   dev8-17     17.96      0.00    594.01     33.07      0.35     19.61      0.99      1.78
09:18:45 AM   dev8-18      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
09:18:45 AM   dev8-19      1.40      0.00     25.55     18.29      0.00      0.29      0.29      0.04
09:18:45 AM   dev8-20      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
09:18:45 AM   dev8-21      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
09:18:45 AM   dev8-32     25.55    742.51    846.31     62.19      0.69     27.04      1.63      4.17
09:18:45 AM   dev8-33     22.55      0.00    844.71     37.45      0.68     30.18      1.41      3.17
09:18:45 AM   dev8-34      2.99    742.51      1.60    248.53      0.01      3.40      3.40      1.02
09:18:45 AM   dev8-35      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
09:18:45 AM   dev8-48     18.16      0.00    645.11     35.52      0.41     22.65      1.09      1.98
09:18:45 AM   dev8-49     18.16      0.00    645.11     35.52      0.41     22.65      1.09      1.98
09:18:45 AM   dev8-50      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00
09:18:45 AM   dev8-51      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00

sar -w output:

12:00:01 AM   cswch/s
05:10:01 AM  51556.52
05:20:02 AM  54484.96
05:30:01 AM  57533.58
05:40:02 AM  57956.67
05:50:01 AM  57885.02
06:00:02 AM  46017.63
06:10:01 AM  21778.29
06:20:01 AM  43464.68
06:30:02 AM  51766.88
06:40:01 AM  53879.12
06:50:02 AM  56531.08
07:00:02 AM  57732.89
07:10:01 AM  57658.24
07:20:02 AM  58209.16
07:30:01 AM  58446.37
07:40:02 AM  58537.84
07:50:01 AM  58243.39
08:00:02 AM  58362.02
08:10:01 AM  58291.73
08:20:02 AM  58370.15
08:30:01 AM  58545.73
08:40:02 AM  58448.40
08:50:01 AM  58198.55
09:00:02 AM  58313.22
09:10:01 AM  58122.85
09:20:02 AM  58517.96
09:30:01 AM  58338.94
09:40:02 AM  58317.30
09:50:01 AM  58312.40
10:00:01 AM  58337.53
10:10:02 AM  58167.55
10:20:01 AM  58408.61
10:30:01 AM  58133.29
10:40:01 AM  58165.08
10:50:02 AM  58240.77
11:00:01 AM  58236.16

Average:      cswch/s
Average:     55991.47

sar -I SUM output:

12:00:01 AM      INTR    intr/s
05:10:01 AM       sum   3825.03
05:20:02 AM       sum   3999.32
05:30:01 AM       sum   4038.10
05:40:02 AM       sum   4041.99
05:50:01 AM       sum   4015.39
06:00:02 AM       sum   3450.48
06:10:01 AM       sum   2385.73
06:20:01 AM       sum   3355.96
06:30:02 AM       sum   3641.50
06:40:01 AM       sum   3807.91
06:50:02 AM       sum   3853.99
07:00:02 AM       sum   3951.29
07:10:01 AM       sum   3996.06
07:20:02 AM       sum   4005.63
07:30:01 AM       sum   3939.43
07:40:02 AM       sum   3901.39
07:50:01 AM       sum   3920.22
08:00:02 AM       sum   3950.27
08:10:01 AM       sum   3926.09
08:20:02 AM       sum   4072.29
08:30:01 AM       sum   4058.93
08:40:02 AM       sum   3994.94
08:50:01 AM       sum   3969.04
09:00:02 AM       sum   3976.33
09:10:01 AM       sum   3904.43
09:20:02 AM       sum   4054.35
09:30:01 AM       sum   4006.06
09:40:02 AM       sum   3962.65
09:50:01 AM       sum   4016.83
10:00:01 AM       sum   4064.52
10:10:02 AM       sum   3934.29
10:20:01 AM       sum   4029.60
10:30:01 AM       sum   3939.23
10:40:01 AM       sum   3937.37
10:50:02 AM       sum   3961.87
11:00:01 AM       sum   4014.83

Average:         INTR    intr/s
Average:          sum   3794.24

Any idea what could this be, or where I should look for more diagnostic information?

Thanks.

I'm trying to diagnose a memory leak in a process, and looking for a tool to graph its memory usage over time.

Is there any tool on Linux that supports diagramming in a form similar to Windows PerfMon?

I tried using IBM virtual assistant, but it works only on 32-bit, while I have 64-bit platform.

Thanks.

Can anyone explain what is the major difference between Heartbeat and UCarp for IP fail-over scenarios?

They both seem to provide this functionality, perhaps UCarp simpler to set-up?

Thanks.

Have anyone ever managed several geographically distributed systems with Puppet?

I have several almost exactly similar deployments (except the server IP's), which management I'm looking to convert to Puppet.

I have 2 options:

• Have each deployment to host it's own PuppetMaster for providing local configurations, then synchronize somehow the PuppetMasters (maybe with puppet again)

• Host the PuppetMaster on AWS EC2 for high-availability, and provide configurations to all deployments from single point

Has anyone tried the second option, and how it worked out? I'm especially interested in High-Availability performance under such environment.

Thanks.

Can someone provide cons and pros for having DHCP in a data center?

I know this is usually a taboo, but maybe there were developments which alleviate the said issues?

Thanks.

I'm interested in Puppet configuration management system, but wonder where the fine line goes between kick-start and Puppet?

Today I do a lot of tasks in kick-start (powered by Cobbler), including some custom partitioning.

Question is, if better to move everything (except custom partitioning and puppet packages) into Puppet, for a more flexible management? Or there are some defined guidelines for this?

Thanks.

I'm looking to switch from password based (which I starting to become overwhelmed with) to SSH keys based system.

I'd like to know if there any SSH keys management system or server solution, which would allow me to distribute and revoke keys over machines?

Or the best approach is to use Puppet for this task? If yes, then would the approach of single key-pair per client machine (described here: Best system for managing ssh keys?) be the best?

What are the downside of cloning vs scripted installation (using Kick-start / Puppet)?

I read a lot of pro-scripted install opinion, where cloning is considered as unreliable method due to ever changing hardware.

In my case the hardware is pretty unified as we use same vendor, and even if it changes, the effort to adapt the cloned image settings (I use SystemImager), wasn't very difficult.

It also much faster, and takes about 5 minutes vs 20 - 30 of scripted installation (without local mirror of course), and is able to capture minor bits which quite difficult to script (MySQL DB securing for example).

But still the cloning gets a lot of flack from what I read, so can anyone share his opinion and experience on this, and if it's worth for me to change our deployment infrastructure to script installation?

Thanks in advance!

Is there any practical difference between using ln -s or mount --bind?

I want to move some folders to another partition, without changing their daemon setting, and wonder what approach I should take.

I prefer ln -s as it requires minimum setup (no /etc/fstab modifications), but perhaps there is a reason why it's not common?

Having learned a bit about LVM mirroring, I thought about replacing the current RAID-1 scheme I'm using to gain some flexibility.

Problem is that according to what I found on the Internet, LVM is:

1. Slower than RAID-1, at least in reading (only single volume being used for reading).
2. Unreliable on power interrupts (requires disk cache disabling for prevention of data loss).

http://www.joshbryan.com/blog/2008/01/02/lvm2-mirrors-vs-md-raid-1/

Also it seems, at least to several setup guides I read (http://www.tcpdump.com/kb/os/linux/lvm-mirroring/intro.html), that one actually requires a 3rd disk for storing the LVM log. This makes the setup completely unusable on 2 disks installations, and lowers the amount of used mirror disks on higher amount of disks.

Can anyone comment the above facts, and let me know his experience of using LVM mirroring?

Is there any performance difference on high-disk usage scenarios, between primary and extended disk partitions?

Thanks.

I read quite a lot of advice to switch from file-image VM storage, to partition/LVM volume based.

The claim is that partition/LVM are much faster then image files.

The downside in my opinion, is that one no longer have the whole VM in a single, easy to copy and migrate file.

Can anyone advice on this, especially if there indeed any difference in new versions of Xen, and if there are any IO benchmarks to support it?

Thanks!

What is faster on the same hardware, Xen or KVM?

I'm trying to pick-up a virtualization technology to work, which gives the best performance.

There are some benchmarks here that I found on the subject: http://virt.kernelnewbies.org/XenVsKVM

They show KVM as a winner, with significant difference in performance - which goes against the idea that KVM is a type-2 hypervisor, and by definition it should be slower than Type-1 hypervisors (like Xen) - or at least that what the articles on the web say.

Any idea on the subject?