Avast 4.8 very slow full system "Quick scan"

Today I did a Standard scan on the same laptop. I got strange results. It took only 38 mins 13 secs and only scanned 10.6gb files. Figure that out! I haven’t removed any programs or files except for cache cleaning with CCleaner.

Interesting, I have never tried a quick scan, only using the standard without archives, I will fire one off and see what that gives.

I just rescanned with quickscan, 41min 13sec, 15.6 gb of files scanned. Strange that a quick scan scans more files that standard scans ??? ::slight_smile: Maybe that explains why quick scans take longer than standard scans ??? ::slight_smile: :stuck_out_tongue:

Maybe the ALWIL team mislabeled the scans ???

Why the inconsistant results ???

Interesting Just ran two scans, a Quick and a Standard, both without archives.

Quick Scan
Total Files/Folders scanned 39,632/3871
Scan duration 16min 11sec
Total scanned file size 7.3GB

Standard Scan
Total Files/Folders scanned 39,671/3872
Scan duration 15min 51sec
Total scanned file size 7.3GB

So they were almost identical, the Quick scan was 20sec slower, but the Standard scan only scanned 39 more files and 1 more folder. So to me it would appear it is a waste of time using the Quick scan when the Standard one is quicker and scans marginally more files.

Compare that with my previous Standard scans (pre 4.8) where the total scanned size was the same, but the duration was only just over 11mins, so an increase in my scan duration of about 41% on the Standard scan. I didn’t take detailed files/folder counts, but the 39,000+ would also be correct.

What a case of tortoise (4.8) and hare (4.7)!

You only have to watch the scans to see something very wrong - a bit like watching paint dry.

I just ran Standard and Quick scans on the same system without archive scanning. One set with avast 4.8 and one set with avast 4.7

Standard 4.8_______________Standard 4.7_______________

42768/4978 7.8Gb 17:33 42031/4975 8.5Gb 11:25

Quick 4.8__________________Quick 4.7__________________

42099/4977 7.7Gb 17:28 16904/4975 5.5Gb 7:30

Observation: The avast 4.8 scans sit for a long period at folders that are very large and full of files in the exclusion list (Standard and Quick). The 4.7 scans zip right through those same folders.

but you shouldn’t forget that there’s also the rootkit scan which is done in 4.8 :o

onlysomeone,

you may have missed this quote from Vlk in another thread:

However, the rootkit scan should not take place if you're performing a "Quick" scan.

From monitoring the file activity it appears that neither standard scan nor quick scan is handling excluded files as efficiently as 4.7.

oh, sorry - i was too lazy to read… :-[

Well, is it only exception handling?
People are reporting slower scans even with no exceptions defined, aren’t they?

but you shouldn't forget that there's also the rootkit scan which is done in 4.8

That does not really add up either - the avast standalone rootkit scan of my system only takes 70 seconds to complete.

I just did an ashquick scan of one of my disk drives (where almost every file on the drive is in the exclusion list)

ashquick (which is actually a thorough scan - but without rootkit scanning) took 00:03

an avast on demand Quick scan of exactly the same drive took 01:44 (considerably longer than the rootkit standalone complete run)

I think there is enough indication that a little problem exists here that I am confident the avast team will take care of quickly.

Vlk,

I have to guess that there are two factors at work but the basic cause is probably the rootkit scan

  1. It is slowing scanning in general (see: http://forum.avast.com/index.php?topic=34314.msg287318#msg287318 ) practically no exlusion apply to this folder
  2. It is causing excessive (directory management I think) I/O on those folders that contain large numbers of excluded files. See the post above this.

By the way … in support of both … I have reported elsewhere here that there is no change in the timing of my weekly whole system ashquick scan between 4.7 and 4.8.

That makes things even more interesting, in the Quick scan there is no rootkit scan and the scan duration is even higher than the Standard scan where a rootkit scan takes place ???

I’m also surprised by that quote of Vlk as I have two event viewer entries (aswar failure) that would appear to coincide with both my Quick and Standard scan. So to me it appears that the rootkit scan is done (or attempted and failed on my FAT32 system) for the Quick scan ?

But how can you know if rootkit scanning was done, or not??

And, by other hand, how can you get a boot scan done?

  1. Difficult as it doesn’t announce it presence, I found it was being run because it was failing and error messages were in the windows event viewer, if it is working a) there won’t be an event viewer entry, b) if you had a rootkit it would have a pop-up alert, c) if you are clean nothing would pop-up.

  2. If you have XP, vista32bit or Win2k, you could enable a boot time scan. Right click the avast icon, select Start avast! Antivirus, Menu, ‘Schedule boot-time scan…’ Or see http://www.digitalred.com/avast-boot-time.php.

And how can you get emergency disks for Avast??

What emergency disks are you talking about (I wasn’t aware there were any, disks other than the BART CD which is costly) ?

Other applications for virus have the option to save emergency disks to use them in case your system goes down. I was surprised as avast seems not to have this option.

I have never heard of that, certainly for any of the AV I have used over ten years or more. I must have lead a sheltered life, I also trust to my own back-up and recovery system.

I use a hard disk imaging application. I also do a daily (or more frequently) back-up all the things that you don’t want to lose, data files, like documents, spreadsheets, emails, email account details, registration keys, address book, favourites/bookmarks, downloaded files/programs, etc. the list goes on and on but if you don’t want to lose it back it up. There are many back-up programs that can simplify this task and run it every day.

I do a weekly image of my partitions and save them to my 2nd hard disk, they can also be saved to off-line storage, DVD, USB external hard disk, etc. as part of my weekly system maintenance.

So if the worst comes to the worst at most I lose:
A. 6 days worth of program updates or new installations, but with my daily back-up I can recover most of that.
B. less than one days data files, emails, etc.
None of these is a problem and much quicker than a system reinstall and I don’t have to go on-line to download the myriad of security updates needed to secure my system where there is a chance to get reinfected whilst my system has vulnerabilities because of these missing patches. Not to mention all my system tweaks and program settings are retained and I will have saved myself many hours of work and a huge amount of stress.

Many of these programs cost, there are some free ones, but it will take some research on your part to find these tools and decide on what is best for you from reviews, user feed back, etc. good luck.

Well, there are many applications that I have never heard of them before. And it can be very hard to find just the information you need, or the best applications to get back-ups or hard disk images, for example, if you don’t know much about them.

BTW is there already a solution to this problem or … do we just have to wait ? 4.8 is so slow that it takes more than 2 hours to scan 2 disks … :frowning: