Calibre 9.1 Constantly Accessing Hard Drive at Start-up

Chris_Snow · 02-05-2026, 07:46 PM

Title says it all. I start Calibre 9.1 and immediately it starts accessing my data drive and doesn't appear to stop. I can hear the HDD working and task manager shows several calibre-worker processes running and the DISK column shows the activity. If I close Calibre the HDD access stops.

I only installed 9.1 a couple of days ago.

I have rolled back to 8.16.2 and there is NO hard drive accessing as 9.1 is doing (yes...it shows several calibre worker processes as well, but the HDD isn't getting flogged)

Been a long time since I needed to ask anything. Calibre as been great.

Unfortunately -> using Winslop 11 😢

I don't run anything tricky

Any ideas what this could be. I did carry out a REPAIR on the 9.1 install, but nothing changed, hence the roll-back.

Thanks

theducks · 02-05-2026, 08:06 PM

It is expected to last a bit for really large Libraries.

1)Calibre added Pages column, used by the shelf view.
2)deleted unused (Calibre ) DB columns
3) #1 , #2 triggers a redo of metadata.opf in the title folders.

Add a really aggressive AV scan (also slows things down)

I ran the beta, so the recrunch happened a while back. Hardly noticeable, but my PC is always on.

Chris_Snow · 02-05-2026, 08:10 PM

Thanks. Just so you know, I couldn't find this post. Didn't see the moderator bit
(doh!) so I posted again. That one can be deleted.

So how come 8.16.2 doesn't do it??

Dal Bhat · 02-05-2026, 08:50 PM

Quote:

Originally Posted by Chris_Snow

Title says it all. I start Calibre 9.1 and immediately it starts accessing my data drive and doesn't appear to stop. I can hear the HDD working and task manager shows several calibre-worker processes running and the DISK column shows the activity. If I close Calibre the HDD access stops.

Any ideas what this could be.

Perhaps it's still doing what it has to do to be able to provide Bookshelf view. When that's finished, should settle down.

My own system has three task mgr lines for calibre:

the main calibre program using 171MB memory and 0-.1% CPU
and two calibre worker process using no CPU and 12.7MB memory each.

No hard drive light at all once the program starts up.

Chris_Snow · 02-05-2026, 09:19 PM

Ducks said Calibre added pages column. Maybe this was only for V9??

If I delete that column, perhaps it will stop?

I already have a pages column for many years (I think I made it myself many years ago) so I didn't immediately click to that.

Need to install V9 again and see.

I keep asking myself if I need to be continuing to upgrade?? Thanks

Chris_Snow · 02-05-2026, 09:57 PM

I've re-installed 9.1.
I'll leaving in crunching and see what happens.

DNSB · 02-05-2026, 10:00 PM

Quote:

Originally Posted by Chris_Snow

Ducks said Calibre added pages column. Maybe this was only for V9??

If I delete that column, perhaps it will stop?

I already have a pages column for many years (I think I made it myself many years ago) so I didn't immediately click to that.

Need to install V9 again and see.

I keep asking myself if I need to be continuing to upgrade?? Thanks

The new calibre 9 Pages column is built into calibre and it's only use is setting the width of book spines in bookshelf view. It is not removable and has nothing to do with the Page count column used by the Page Count plugin. Though you can set the width to use the Page Count pages algorith. Heck, at one point in the beta test, I use Page Count's word count to set the spine width just to see what could be done.

On my system which is a bit of a high end machine, it took ~10 minutes to generate all the page counts for my main library. Slower machines will take longer but this is a background task so has little effect on anything else. Once the page counts were completed, it takes a few seconds after calibre startup with my main library open for the disk activity light to go out.

theducks · 02-05-2026, 10:05 PM

Quote:

Originally Posted by Chris_Snow

Thanks. Just so you know, I couldn't find this post. Didn't see the moderator bit
(doh!) so I posted again. That one can be deleted.

So how come 8.16.2 doesn't do it??

It is part of 9's new features.

BetterRed · 02-05-2026, 11:02 PM

In the beta test thread I seem to remember the developer of shelf-view (un_pogaz) mentioned the page count calculation runs at about 1,000 books an hour on his rig.

BR

DNSB · 02-05-2026, 11:58 PM

Quote:

Originally Posted by BetterRed

In the beta test thread I seem to remember the developer of shelf-view (un_pogaz) mentioned the page count calculation runs at about 1,000 books an hour on his rig.

Which is why I mentioned that my machine is on the high end (i9, 64G RAM, dual PCI4 NVMe hard drives) when giving my times for calibre's page counter and my main library.

kacir · Yesterday, 03:36 AM

Quote:

Originally Posted by theducks

3) #1 , #2 triggers a redo of metadata.opf in the title folders.

No. The metadata.opf is not being overwritten. Kovid told me as an answer to a direct question about it. And it would be very easy to verify.
https://www.mobileread.com/forums/sh...52&postcount=4

It is simply all the books being accessed to count pages for them. If the books are on a spinning drive it might take a while. People reported large number of books being scanned per minute on an SSD with a fast processor and enough memory.

BetterRed · Yesterday, 05:30 AM

Quote:

Originally Posted by kacir

No. The metadata.opf is not being overwritten. Kovid told me as an answer to a direct question about it. And it would be very easy to verify.
https://www.mobileread.com/forums/sh...52&postcount=4

It is simply all the books being accessed to count pages for them. If the books are on a spinning drive it might take a while. People reported large number of books being scanned per minute on an SSD with a fast processor and enough memory.

The Shelf 'pages' calculator uses the book format file size to compute its value… that generates disk i/o

But that information is already available in the 'data' table of metadata.db. If the bookshelf 'page' calculator used that information I suspect it would speed up the initial scan by quite a lot… especially if that table is already loaded into calibre's in memory rendition of the database.

Click image for larger version

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BR

Chris_Snow · Yesterday, 04:07 PM

Thanks for all the insights.

I left the PC running.
The library is on a 3.5" HDD.
It took several hours to complete, but now appears to work as expected -> meaning there is now NO HDD accessing when Calibre starts.

So...I guess I am good to go!

Dal Bhat · Yesterday, 07:14 PM

Quote:

Originally Posted by Chris_Snow

I guess I am good to go!

While you're going, get yourself an SSD.

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02-05-2026, 07:46 PM	#1
Chris_Snow Groupie Posts: 153 Karma: 8170 Join Date: Jul 2013 Device: kobo glo	Calibre 9.1 Constantly Accessing Hard Drive at Start-up Title says it all. I start Calibre 9.1 and immediately it starts accessing my data drive and doesn't appear to stop. I can hear the HDD working and task manager shows several calibre-worker processes running and the DISK column shows the activity. If I close Calibre the HDD access stops. I only installed 9.1 a couple of days ago. I have rolled back to 8.16.2 and there is NO hard drive accessing as 9.1 is doing (yes...it shows several calibre worker processes as well, but the HDD isn't getting flogged) Been a long time since I needed to ask anything. Calibre as been great. Unfortunately -> using Winslop 11 😢 I don't run anything tricky Any ideas what this could be. I did carry out a REPAIR on the 9.1 install, but nothing changed, hence the roll-back. Thanks

02-05-2026, 08:06 PM	#2
theducks Well trained by Cats Posts: 31,478 Karma: 62503914 Join Date: Aug 2009 Location: The Central Coast of California Device: Kobo Libra2,Kobo Aura2v1, K4NT(Fixed: New Bat.), Galaxy Tab A	It is expected to last a bit for really large Libraries. 1)Calibre added Pages column, used by the shelf view. 2)deleted unused (Calibre ) DB columns 3) #1 , #2 triggers a redo of metadata.opf in the title folders. Add a really aggressive AV scan (also slows things down) I ran the beta, so the recrunch happened a while back. Hardly noticeable, but my PC is always on.

02-05-2026, 08:10 PM	#3
Chris_Snow Groupie Posts: 153 Karma: 8170 Join Date: Jul 2013 Device: kobo glo	Thanks. Just so you know, I couldn't find this post. Didn't see the moderator bit (doh!) so I posted again. That one can be deleted. So how come 8.16.2 doesn't do it??

02-05-2026, 09:19 PM	#5
Chris_Snow Groupie Posts: 153 Karma: 8170 Join Date: Jul 2013 Device: kobo glo	Ducks said Calibre added pages column. Maybe this was only for V9?? If I delete that column, perhaps it will stop? I already have a pages column for many years (I think I made it myself many years ago) so I didn't immediately click to that. Need to install V9 again and see. I keep asking myself if I need to be continuing to upgrade?? Thanks

02-05-2026, 09:57 PM	#6
Chris_Snow Groupie Posts: 153 Karma: 8170 Join Date: Jul 2013 Device: kobo glo	I've re-installed 9.1. I'll leaving in crunching and see what happens.

02-05-2026, 11:02 PM	#9
BetterRed null operator (he/him) Posts: 22,277 Karma: 30317806 Join Date: Mar 2012 Location: Sydney Australia Device: none	In the beta test thread I seem to remember the developer of shelf-view (un_pogaz) mentioned the page count calculation runs at about 1,000 books an hour on his rig. BR

Yesterday, 04:07 PM	#13
Chris_Snow Groupie Posts: 153 Karma: 8170 Join Date: Jul 2013 Device: kobo glo	Thanks for all the insights. I left the PC running. The library is on a 3.5" HDD. It took several hours to complete, but now appears to work as expected -> meaning there is now NO HDD accessing when Calibre starts. So...I guess I am good to go!

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