Software :: Log File Size When Mirroring With LVM2
Feb 11, 2010
I'm going to be using LVM2 to mirror 2 250GB drives for redundancy and fault-tolerance. As per the best docs I have found on mirroring [URL], I am going to keep the log file on a separate physical volume, however I can't seem to find anywhere a good reference for how much size I need to save for the log file. Everything says "small," but "small" doesn't really help in the real world :-).
I have plenty of space on the 3rd pv but want to leave as much of it as possible for other stuff. Should I leave 32MB ? 500MB ? 1GB?
The system never uses more than about 250GB of HDD at any one time, so I would like to remove /dev/sdd1 and /dev/sdc1 from the LV and then from the machine and leave /dev/sda and /dev/sdb alone.
Does anyone know that if I use the command "system-config-lvm" to reduce the total LVM size to say 580GB, whether all data is preserved (I don't have any way at this stage to backup up 250GB of data, unless I buy more HDDs and that is the whole point of this exercise anyway - remove the two terrabyte drives to be used as backup disks).
Once I am happy that the data is safe, I will use "pvmove" and "vgreduce" to remove both terrabyte drives.
I have two web servers. One is active and one is in reserve. I keep the user data (web pages) in sync by running rsync every 10 minutes or so. This copies any changes from the active machine to the reserve machine. But, it's slow, only gets changes every 10 minutes, bogs down the disk, does strange things to files that are changing during the rsync process etc...
I want something that will automatically copy any changes from the active server to the reserve server as they are made. IE I hit 'save' on the active server, it copies the file to the reserve server. Simple!
I've been looking around and I see GFS which is really vastly more complicated than I need. I'm happy with read-only access on the reserve host, so I don't need distributed lock management.
I could theoretically implement this by setting inotify watchers on every file and running an SCP or rsync command when a file gets saved. So, it can't be that hard.
I do not need a true networked file system, as in something I mount over the network. I just want something to keep my disks in sync.
Blue sky thinking at the moment:I have a number of file servers, each at different sites. I would like to be able to make these appear as one, so that files on any server can be accessed from any site, and the user doesn't even see there are multiple servers.Obviously, the internet is slow, especially the upload speeds. So when a file is written the write ought to go to the server on the client's LAN - even if it was previously on another of the servers.However, for robustness, some sort of background mirroring is also wanted. If all the servers were left on and connected, they eventually end up all in sync. But this mirroring needs to be mindful of bandwidth usage; if someone writes a big file to their local server, copying that to the other servers can't interfere with normal internet usage.I think UnionFS or similar might be able to handle the unioning side, but not the mirroring stuff.
Is there any software that will do full mirroring between a local and a remote file system. I have a server (9.04) and a laptop (9.10). Each user has shared a shared directory on the server, and on the laptop. Updates to files may be done on either system. I want to keep both copies syncronised. Currently I use a script based on rsync (scheduled by cron) to keep the local and remote copies in sync.
The problem with this approach is that rsync only seems to be able to handle deletion of files if one file system is the master, which is not the case in my set-up. If I move a file to a different directory, rsync will reinstate the old file as well as copying the new one. I was hoping there was some software that could do proper mirroring between the 2 systems, but6 so far I cannot find anything.
is lvresize with --resizefs options re-size the Logical Volume and then re-size the file system? i mean we don't need to use resize2fs?I looked at man pages but it doesn't explain this option.
I need to install a lvm2 group with encryption and have the /boot file stored within. Is this possible in Fedora's graphical installer? I know it can be achieved in Arch(I know I'll need grub2, I assume that's coming in Fedora 12) I can always install it separately.
I am curious if perhaps I am doing something wrong extracting pages from a pdf doc using pdftk and creating a new file. I am only extracting the odd pages from the file and outputting them to a new file that is now only 20 pages instead of the input's 40 pages, yet the new output file is still 1.4Mb in size, the same as the original.
It seems strange to extract only half the pages of a large document and end up with a result that is the same size. how to streamline the resulting pdf's using pdftk?
BTW this is the command I am using, in case perhaps I am missing an option to optimize file size or something:
I'm researching about symbolic links been used with samba / CIFS:I'd like that the user that uses a MS-Windows OS could see my shared folder on CentOS 5 and the symbolic links that are inside this folder. Well, it works but, the user will see that the size of the file is bigger than the real file. Apparently, CIFS gets the size of the symbolic link (aproxim.32K) and add it to the size of the file.Example 1: 100KB file, used with shared folder, MS-Windows's user will see 100KBExample 2: 100KB file, used with symbolic link inside a shared folder, MS-Windows's user will see 132KB. (Sym link + size of file)Is there a way to allow the user only see the size of the file, and not the file + symbolic links ?
I was just testing specifying limit on file size to a user and have added the following to /etc/security/limits.conf bob soft fsize 100 This basically should have said not to allow bob to create anyfile greater than 100Kb in size.
But the interesting thing is, if bob already has any file which is greater than 100Kb in size, it even doesn't allow to log him into the system both from console and SSH. Also nothing is logged in logs.. How do I configure it so that, bob can login to the system even though he has any file greater than 100Kb (but doesn't allow him to create file which are greater than 100Kb) ??
We have some large files with sampling data in it. Don't want to delete these files. But want to quickly overwrite the file with 0s and/or 1s and preserve the original file size.
I am using DD to backup entire system partitions and now I am trying to restore one. The resulting disk image from my buggy process has zero bytes. D'oh.It apparently thinks the image was trailing garbage and ignores it. It deletes the original file and replaces it with a zero byte .dd file. I have the original copy of the image in a dd.gz file. It's 6.3 GB so it may still contain the data.How do I get the original image back without destroying it again?
I have several SLES 11sp1 servers and using SMT (Subscription Management Tool) to provide local mirroring and prevent all the unnecessary web traffic to update all these machines.
I found this article which is working out quite nicely to mirror the openSUSE 11.3 Updates which prevents all my openSUSE 11.3 machines from all going out getting the same update.
Code:
[URL]
I am looking to try and do the same with openSUSE 11.4 and with openSUSE 11.4 using the Tumbleweed repos. Has anyone done this or can someone provide some insight on what I need to do. I am thinking I can run this command
I should use* to provide me with openSUSE 11.4 Updates. For the Tumbleweed repo would I do the same and would that work?
Code:
smt-setup-custom-repos --name OpenSUSE_Tumbleweed --description "OpenSUSE Tumbleweed" --exturl http://download.opensuse.org/repositories/openSUSE:/Tumbleweed/standard/ --productid *don't know what productid I should use*
Again I don't know what productid I should use or if it really even matters, could I use one that is not being used? I am trying to limit how many machines go out to the Internet to pull down updates. I would really like to have one system (SMT) pulll down any new files and all my clients get their updates from the SMT server.
I've got a repository (3rd party, but not a launchpad one) in my APT sources list that takes a long time to respond on apt-get update.What I was wondering was if I could keep a local mirror of just that repository, and have apt-get update refer to it instead of the normal one, then leave a cron job to check the normal one for any updates.
I've set up a test machine with Ubuntu 10.04. It has two drives making one RAID 1 drive using mdadm. This RAID drive is where /home is mounted. I like to break things just to see what happens and to know what to do to resolve it before it happens for real. So I physically removed one of the drives that made up the RAID 1 (while it was off).
I then rebooted the machine. I thought since it was mirrored then /home would mount correctly using the other mirror. What actually happened was on the Ubuntu splash screen it said there was a problem mounting /home. I skipped the mounting, logged in and looked in /proc/mdstat. It reported one drive that was inactive it did not report the missing drive.
Currently I backing up the MBR, the C and the other partitions to an external USB HDD and from there I restore them if needed. I use the SystemRescueCd and commands like dd if=/dev/sd* of=/mnt/PC_name/backupmbr.1 count=1 bs=512 and ntfsclone --save-image --output /mnt/PC_name/PC_name_c.img /dev/sd*1 etc. I want to clone the HDD the way, however, that I omit the external USB drive. I want to connect the new HDD to the PC and do the cloning directly from one disc to the other.
My questions are:
- Can you provide me with the exact command? - Is that a difference if the disc is SATA or IDE? - Can I copy the disc even if the old disc don't wan to boot?
I have a mail server on Fedora 8. I would like to have a mirror to this server so that it takes over in case my server goes down.I dont know how to go about it.
I've always been under the impression that when using the console only a notebook's display is used. Apparently this is not the case as I just booted off of a SystemRescueCD and the display on the notebook was mirrored on my external HDMI connected monitor. I have a feeling this is set somewhere in the kernel, but where?
At some point my wine install died. I haven't used it a lot and I update my Fedora 11 regularly so I'm not sure what made it break. I thought "ok, just see if there's an updated version". 'yum info wine' says there is an update version and the file is 27k in size. Tried installing and no joy. Tried erasing wine and then installing; no joy. Yum says that the X86-64 and the i686 version are both 27k in size. I know for sure that is wrong. On a semi-nonFedora note, I tried compiling my own version of wine. It compiled fine after installing some dependencies and '-devel' files, but it gets the same crash as the Fedora version was getting.
I have a large number of folders that each contain quite a few files of varying sizes (from a few bytes to 400kb or so), mostly smaller ones. I need to get the actual (not the disk usage) size of these folders. Is there any way to do this with a command like 'du'?
Is there a maximum size of file that soundKonverter can deal with? I can convert a 10.4MB wma file to mp3, but am unable to convert a 40.2MB wma to mp3 (it produces only a 0byte mp3 file). I'm using it under Hardy Heron.
I made 272 Photos from one book. Total size was 920MB. I used than gscan2pdf to create pdf document, and reduced there quality size. Result 116 MB. Than i converted it to grayscale [URL] with:
