7z Compression can Recuce Signature File Size to 66% of the Original Size

As many signatures are added to CIS/CAV I notice how the bases.cav file is growing very large. The latest database right now (1170) is no less than 86.6 MB.

I made a .7z file out of the enormous bases.cav file, and the result was a file with 66% size of the original bases.cav file. Of course I realize that implementing 7z compression of the signatures may cause slowdowns, but I’m curious about Comodo’s plans for future signature formats. Are you expecting a reduced file size?

Let me also emphasize that I’m more interested in low system resource usage, which you’ve already achieved with CIS/CAV, rather than low disk space usage. If we however can get both things, I’m one of the first to applaud it, as I try to minimize my system disk usage (I’m currently using just 1.17 GB for a fully patched Windows XP SP3 and all applications, like CIS, OpenOffice.org, PDF and 3D software :-TU).

Thanks. :slight_smile:

I am not sure compressing it would cause slowdowns. Unless 7z is very resource heavy when decompressing it would be faster for the same reasons why compressing Windows system files makes the OS faster.

That makes me wonder whether the definitions files get sent compressed or not.

It would be nice to see a highly compressed installer, go form a 75MB installer to one that is less than 30MB. Also this compression would be great when downloading new signatures. This would make it a fast download and once on the hard drive CIS could unpack them.

Yeah the signature sizes are quite large.

Yes, it’s a bit strange to see a security suite so easy on memory resident resources, yet quite the ungainly download size.

Leoni, interesting to see that that the file size decreased significantly when u compressed it, as i see antivir (avira) antivirus give the update file in .zip format(in offline updates) if comodo antivirus updates also come in such format it would take less time downloading them.
As i seen decompressing 7z dont take high resources either so it might be worth idea to look into by comodo team.

To tell you the truth I forgot to decompress before I deleted the file, so I don’t know how 7-Zip would react on the decompressing action.

I can tell you though that I experienced heavy resource usage from compressing. I had to pause 7-Zip in order to launch my browser, it simply wasn’t possible else. But of course, what CIS would need to do in order to match memory & file scanning with signatures, would be decompressing. To the best of my memory, decompressing can be very fast with 7z / 7-Zip.

1171 is 84.5 MB. ??? I compressed it to 55.7 MB.

Only 690 MB RAM usage… 88)

Seriously, who cares about the size, even if it was 1TB I’d still be happy.

Those with slow internet connections might care.

Actually thats not true and a very same reason why none of the Windows files are compressed by any packer.
First because it could trigger false positives by products like CIS (■■■■■■ packer detection) and because every decompression of a file requires CPU time. It’s not a problem when you execute 1 or 2 runtime compressed programs, but could be a problem if system would have to decompress 100 DLL files at the same time.
CPU usage spikes would most probably appear, especially on low end CPU’s. A block of free memory is also needed for decompression. Around 60MB for LZMA “Ultra” profile decompression. 1 file!
Now multiply that and you have a problem.

Compressing installer properly however is another thing and that is possible.
Not sure why they use ZIP SFX. It’s totally ■■■■■■.
CIS 3.9 32bit compressed from massive 118MB to just 57,8MB using 7-zip LZMA (Ultra profile).
Thats almost half the size.

I don’t have a slow internet connection, and if you have you have to wait a little longer, I had that few years ago as well and that’s how things work. Either get a better internet connection or wait a while.

You don’t, and I don’t, but we’re not the only ones. You forget that some people can’t get such connections due to technicalities and/or costs. Reducing file sizes will significantly help these people in downloading and maintaining CIS.

EDIT: Here’s just one example among many. https://forums.comodo.com/empty-t39461.0.html

Exactly there are many users who are on slow speed internet, For them it will be good if update size is low.

Precisely. Of course everyone will eventually be able to easily handle a large database - but today is today and many thousands of users would benefit from a reduced file size, today and tomorrow.

When I was on dial up, I actually stopped using a few applications that had broadband-centric file sizes. It’s just not very practical to depend on 3 hour update downloads to keep some software current. Sure, you can start downloading and go to bed, but more often than not, you get disconnected at some point. Downloads managers helped immensely, but it was still a large hurdle.

Luckily I wasn’t metered on my connection, but you need to remember that there are users that have to pay by the MB. If someone needs to fork out a lot of money for each update, I don’t think they’d be users long.

I am already looking forward to the introduction of family signatures as that, I guess, may also help to reduce the size of the updater files .

I’s say download size is more critical than CPU time…? Otherwise we’d still be using BMP images.

I have a 7z archive that’s 3.8 MB; unzipped: 180 MB. I’m amazed by 7z’s capabilities.

Atleast the update file should be compressed to save dl times…