Marco Shaw's questions

I'm having an issue with performance on a Red Hat VM, seemingly related to a Java process that seems to be quite heavy on processing and data. I'm been working through different things, but nothing has improved the performance so far.

I currently have this VM on a host, and have confirmed that I have leftover virtual processors once I calculate the core/socket/threads.

I don't understand how/why the "CPU ready" of the VM would be non-zero when the host is underutilized for vCPUs.

Won't a non-zero value potentially mean the VM is getting shifted around semi-randomly to different CPUs?

Perhaps I'm missing something obvious... I guess I'd want to try to pin the VM to same vCPUs as a test.

Sorry, newb...

I'm just trying to figure out if it's worth figuring out how to connect JMC remotely to a server to look at a JVM issue... If I use Flight Recorder to record the log, is that log basically the same thing as taking the resulting log file and loading that into the JMC where I can launch the UI?

I followed this: https://www.debugpoint.com/2021/03/how-to-update-or-upgrade-ubuntu-offline-without-internet/

I'm trying to test an offline upgrade from Ubuntu 16 to 18.

The "offline-data-dir" created just now is only 40MB. That can't be right?

I copied that data to a Ubuntu 16 and pretty much nothing happened when I ran apt-offline install offline-data-dir/.

If I understand... I can run apt-offline from the Ubuntu 18 machine, copy the offline directory to my Ubuntu 16, then just run the above install command?

I guess I would have expected the offline directory to be a few GB at least.

Cross posting from SO: https://stackoverflow.com/questions/69722698/using-an-ip-address-and-port

Ubuntu 18/Varnish 4.x

I'm not sure what I'm missing.

The documentation (http://manpages.ubuntu.com/manpages/xenial/en/man7/varnish-cli.7.html) seems to suggest:

...
backend.list [-p] [<backend_expression>]
  List backends.
...
Backend Expression
  A  backend  expression  can be a backend name or a combination of backend name, IP address
  and port in "name(IP address:port)" format.
...

However, I don't know if I'm missing something because I can't pass an IP address or port seemingly in Ubuntu 18 to list or set to auto/sick:

varnish> backend.list *www*
200
Backend name                   Admin      Probe                Last updated
xxx-www-5          probe      Healthy             5/5 Fri, 22 Oct 2021 08:36:34 GMT
xxx-www-5http      probe      Healthy (no probe)   Sat, 16 Oct 2021 18:52:41 GMT
varnish> backend.list *10.105*
200
Backend name                   Admin      Probe                Last updated
varnish>

Any ideas? Is this a documentation error and Varnish 4.x doesn't accept IPs?

Other relevant information:

Varnish config:

    ...
    backend xxx-www-5 {
            .host = "xxxweb05";
            .port = "xxx443";
    ...
    }
    backend xxx-www-5http {
            .host = "xxxweb05";
            .port = "xxx80";
    ...
    }
    ...

$ nslookup xxxweb05
Server:         127.0.0.53
Address:        127.0.0.53#53

Non-authoritative answer:
Name:   xxxweb05.xxx.com
Address: 10.105.xxx.xxx

I was surprised to find two of my environments had different setups. One has a DOS partition style, while the other does not appear to have any kind of table defined whatsoever.

I'm sort of familiar with the concept where Oracle, for example, sits on a raw disk, is that the same here? Can XFS simply sit on a raw disk with no partition table?

For example, this disk has a fully working XFS FS. I've been able to resize it, etc. over the last few years.

# fdisk -l /dev/sdc

Disk /dev/sdc: 644.2 GB, 644245094400 bytes
255 heads, 63 sectors/track, 78325 cylinders, total 1258291200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x08020000

Disk /dev/sdc doesn't contain a valid partition table

I'm in a bit of a pickle. I tried to upgrade a chroot'ed environment and it seems I broke dpkg in the process.

I don't know if the cause of the problems is that apt-get isn't able to handle a qmail upgrade or if it's something else (it seems snmpd also didn't "finish" during the last round).

I think the error I'm trying to address is:

E: Sub-process /usr/bin/dpkg returned an error code (1)

It seems I have a very old version of qmail, and upgrading to the one in my apt mirror is too much of a change. I've googled, and have not been able to find anything between 1.03-38 and 1.06-5 yet.

(Removed a few lines and struggled with the formatting)

# apt-get install qmail

The following extra packages will be installed:
  qmail-run qmail-uids-gids
Suggested packages:
  dot-forward qmail-tools
The following NEW packages will be installed:
  qmail-run qmail-uids-gids
The following packages will be upgraded:
  qmail
1 upgraded, 2 newly installed, 0 to remove and 1 not upgraded.
107 not fully installed or removed.

Do you want to continue [Y/n]?
Get:1 http://10.105.176.67/debian/ wheezy/main snmpd i386 5.4.3~dfsg-2.8+deb7u1 [964 kB]
Fetched 964 kB in 0s (6,685 kB/s)
Can not write log, openpty() failed (/dev/pts not mounted?)
(Reading database ... 1852018 files and directories currently installed.)
Preparing to replace qmail 1.03-38 (using .../archives/qmail_1.06-5_i386.deb) ...
Upgrading from qmail version 1.03-38 is not yet supported.
dpkg: error processing /var/cache/apt/archives/qmail_1.06-5_i386.deb (--unpack):
 subprocess new pre-installation script returned error exit status 1
rmdir: failed to remove `/var/lib/qmail': Directory not empty
insserv: warning: script 'K01qmail' missing LSB tags and overrides
insserv: warning: script 'qmail' missing LSB tags and overrides
dpkg: regarding .../qmail-uids-gids_1.06-5_all.deb containing qmail-uids-gids:
 qmail conflicts with qmail-uids-gids
  qmail-uids-gids (version 1.06-5) is to be installed.

dpkg: error processing /var/cache/apt/archives/qmail-uids-gids_1.06-5_all.deb (--unpack):
 conflicting packages - not installing qmail-uids-gids
dpkg: regarding .../qmail-run_2.0.2_all.deb containing qmail-run:
 qmail-run conflicts with mail-transport-agent
  qmail provides mail-transport-agent and is present and installed.

dpkg: error processing /var/cache/apt/archives/qmail-run_2.0.2_all.deb (--unpack):
 conflicting packages - not installing qmail-run
Errors were encountered while processing:
 /var/cache/apt/archives/qmail_1.06-5_i386.deb
 /var/cache/apt/archives/qmail-uids-gids_1.06-5_all.deb
 /var/cache/apt/archives/qmail-run_2.0.2_all.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

Specifically for Wheezy, does anyone know if some of the existing mirror scripts still work or can point me in the right direction to start?

For example, will Debmirror work with archive.debian.org? https://help.ubuntu.com/community/Debmirror

I've installed the latest debmirror to my Ubuntu 16 "mirror server" (my working local Ubuntu 16 mirror and hoping it can also be a local Wheezy mirror).

I'm assuming it does some kind of "rsync over http". A small section of the error output:

+ debmirror -a i386 --no-source -s main,restricted,universe,multiverse -h archive.debian.org -d wheezy,wheezy-security,wheezy-updates -r /debian --progress --method=http /[REMOVED]/DebianMirror
Mirroring to /array0/DebianMirror from http://archive.debian.org/debian/
Arches: i386
Dists: wheezy,wheezy-security,wheezy-updates
Sections: main,restricted,universe,multiverse
Pdiff mode: use
Will clean up after mirroring.
Attempting to get lock ...
Updating remote trace files (using rsync) ...
rsync: failed to connect to archive.debian.org (217.196.149.234): Connection refused (111)
...
rsync error: error in socket IO (code 10) at clientserver.c(128) [Receiver=3.1.1]
Warning: failed to use rsync to download extra files.
Getting meta files ...
[  0%] Getting: dists/wheezy/Release...          #** GET http://archive.debian.org/debian/dists/wheezy/Release ==> 500 Status read failed: Connection reset by peer (1s)
failed 500 Status read failed: Connection reset by peer
...
failed 500 Status read failed: Connection reset by peer
Errors:
 Download of dists/wheezy/Release failed: 500 Status read failed: Connection reset by peer
...
Failed to download some Release, Release.gpg or InRelease files!
WARNING: releasing 1 pending lock...

I'm either not very good at searching or not very good (in general).

What's the meaning of "Version" here? The version of GCC used to build the package?

# dpkg -s linux-image-3.2.0-4-amd64|grep Version
Version: 3.2.96-2

I have a very old system:

# uname -a
Linux [REMOVED] 3.2.0-4-amd64 #1 SMP Debian 3.2.96-2 x86_64 GNU/Linux

I need to update it to the latest available kernel version. For example, I'm trying to find 3.2.101-1 or newer.

Shouldn't this be the linux-image package and I should find it here? http://archive.debian.org/debian-archive/debian-security/pool/updates/main/l/

I pretty much followed the same general idea as here: Resizing a partition

-Resize VMware disk: Through vSphere, resize disk from 100GB to 300GB
(Reboot VM)
-Delete partition
(fdisk /dev/sdb, d, 1)
-Recreate partition
(While still in the same fdisk session with /dev/sdb, n, p, 1, <defaults>)
(Reboot VM)

Unfortunately, now the XFS FS will no longer mount.

I'm basically getting a "bad superblock" error. What I'm looking around is where does the SB actually reside? Is it in a partition or at the very beginning of the disk?

Now:

When I try an xfs_repair -n, it scans for quite some time and eventually gives up.

xfs_repair -n /dev/sdb1
Phase 1 - find and verify superblock...
bad primary superblock - bad magic number !!!

attempting to find secondary superblock...
.....<> .....
found candidate secondary superblock
unable to verify superblock continuing...
.....<> .....
Sorry, could not find valid secondary superblock
Existing now.

When I deleted and recreated the partition, should I have noted the starting position? What I now notice is that partition 1 seems to default to a start of 2048, but what I noticed on similar systems, is a start of 63.

Yes, I didn't think that recording the start of the old partition before deleting it was important. It never came up in all of my recent searching and it is perhaps the key here.

Perhaps my original superblock is in the 63-2048 range? I've copied the VM so that I can try a few things without toying too much with the original VM. Unfortunately, that copy was taken after I broke the original.

UFS Explorer https://www.ufsexplorer.com/ufs-explorer-standard-recovery.php, which came up during searches, sees the XFS file system and seemingly all its contents (via a scan of the VMDK).

Debian 7 VM on VMware ESXi 6

I have a disk SDC (MSDOS partition table) that was originally created as 300GB. One primary partition was created at 300GB. Then XFS was created on that.

I was able to fully test an increase, but there was no partition on my test machines (I inherited this environment). This worked easily:

-Shutdown VM
-Resize disk in VMware to 600GB
-Run xfs_growfs -d /dev/BLAH (I guess XFS can be created on a "raw disk" without a partition?)

That worked!

Now, on my prod system, there's a partition SDC1 on the disk(!). I was able to make this work eventually, but it makes me nervous deleting a partition:

-Shutdown VM
-Resize disk in VMware
-Remove primary partition (300GB), and write to disk
-Recreate primary partition with new size (600GB), and write to disk
-Restart VM (OS refused to see new partition table until a reboot)
-Run xfs_growfs -d /dev/BLAH

The big deal is that I'm dealing with over 250GB of data on this disk I'm resizing.

I will plan a backup, etc., but is this normally safe?

(I just thought... I'm going to test deleting the partition and not recreating it at all, in case I have to grow again down the road.)

Server 2008/2008 R2

I'm trying to remotely monitor these servers to watch the progress of hotfixes being installed. I was able to find this in Server 2003/2003 R2: -Log: System -Source: NtServicePack

It seems the above event is written when every hotfix is installed.

I can't seem to find a comparable entry in Server 2008/2008 R2 though. Is there anything similar that I can easily monitor for remotely?

The only con I can think of when doing full backups all of the time is the speed to recovery when one needs to do a full+incremental+incremental+etc. to get a certain state back.

Why might anyone want to do full backups all of the time/every day? I'm scratching my head wondering why one might need a full all of the time. And that in any circumstance.

I recently thought, well we need nightly fulls on your DB server, but even that's not the case really. The backup client will know the DB dump file has changed, and just back up the changed dump file without trying to backup everything else that hasn't changed from the day before.

Comments?