Unison keeps directories in sync



I started using Unison today. It was the missing part of my backup strategy. My backup strategy is to have mondorescue run on each of my linux servers once a day. This creates one or more .iso files that can be burned directly to a cd, which would be bootable. Therefore, even if the system is not bootable, you can still restore with this cd. You can also use mondo directly and restore from the .iso file.

Once the .iso is created locally on the server, I use rsync to transfer it to a repository, where I store all my backups on a removable IDE drive. I have 2 drives like that, and I wanted to be able to bring one home every weekend, to make sure we don't loose data in case of a fire. I didn't need Unison just for that. The thing is that this server is also a repository for Symantec Ghost images, and I wanted to always have the most recent images on the hard drive. The solution? Well, I tried a simple tar, but that lasts 30 minutes. Unison recognizes which files has changed and copies only those ones. So if no image has changed, it takes about 1 second do complete.

Comments

Post a Comment

Popular posts from this blog

General linux performance troubleshooting

Here's a list of commands that you should execute and then share the output to someone who can help you figure out what resource is the bottleneck in your system. Note, it requires the  sysstat  and  procps  packages (ubuntu and RHEL and its derivatives): uptime vmstat 1 10 iostat -xN 2 10 mpstat -P ALL 3 10 pidstat 1 10 free -mw (or free -m, if your OS doesn't support -w)  uptime is to see the load averages on the system. vmstat is mostly used to tell if the system is swapping or not. If you see significant numbers in the 'si' and 'so' columns, your system is most likely swapping (using the hard drive as RAM), which usually slows performance a lot. iostat is mostly used to determine if your disk subsystem is not able to cope with the load. If you see one or more lines that shows 100 or close almost constantly, it is probably the case.  If it is your swap volume, you probably saw numbers in the 'si' and 'so' columns in the  vmsta
Read more

Asterisk works under OpenVZ (no zaptel)

Hi, Just to let you know that I did a basic test with asterisk on an OpenVZ VE and it works. We only tested SIP connectivity (it would probably be complex to have Zaptel support and I don't really need it). We were able to connect to a VoIP provider using SIP ( unlimitel ) and music on hold works. The only thing I had to change to make it work is to comment out this line in /usr/sbin/safe_asterisk: #TTY=9 # TTY (if you want one) for Asterisk to run on (I guess there is no TTY9 (console # 9) on openVZ since it is a virtual machine and TTY9 is usually a physical console (monitor)). I'll soon put my asterisk server in a VE, I'll let you know how it goes. I also use Unlimitel and ATAs to link my PSTN line and cordless phones.
Read more