Change "Extra Copies" in Greyhole

[sleife]

Hey everybody

Short but important question for me. Can i change the "extra copies" Parameter in Storage pool from "always max" to 2 or 3 ?
What i have to attend?

Look at the picture

[bigfoot65]

Yes you can, it's your choice. Keep in mind that reducing it from Max will change where copies of your files are stored. Greyhole has a formula to do that, but should one drive go bad and it has the only copy of a file, you would lose it.

The number of copies is based on how many drives are in the storage pool of course, so if you only have 3, changing it to 1 or 2 will not give you 100% redundancy for recovery.

I may be mistaken, but that is the way I understand it.

[sleife]

But If I chose 1 copy. then i have to 2 copies of the file?

Beacuse the original file and the copy file iam right with this?

[bigfoot65]

Not 100% sure as I have mine set to max. I have a symlink in my share and 1 copy on each drive, with is 3. So technically I only have 3 real copies.

I am no expert, but it appears that anytime you set copies to less than max, but at least 1 there will be a symlink created in your share. It will point to 1 copy of the file on other drives.

My thought is if you are running with 1 OS drive and 1 Greyhole drive, setting it to 1 would yield only 1 real copy in theory. Then if that 1 Greyhole drive dies, you would have a symlink pointing to nowhere. Not sure if that is correct, but that's the way I see it.

[theophobus]

But If I chose 1 copy. then i have to 2 copies of the file?

Beacuse the original file and the copy file iam right with this?

Correct! But it takes some time until greyhole deletes the extra copy, you can force a fsck and do not forget to clean your attic. I have standard of +1 and for more precious data i max out.

[sleife]

Ok thank you.

When i change the Number of copies, how long does it take if greyhole runs the --fsck and clean the attic?
Is this done in 1-2 days or 1 week?
Just for my information , i didn't find anything in the internet.

[theophobus]

Ok thank you.

When i change the Number of copies, how long does it take if greyhole runs the --fsck and clean the attic?
Is this done in 1-2 days or 1 week?
Just for my information , i didn't find anything in the internet.

greyhole usually does a regular fsck on a daily base, as far as I know. You have always to clean the attic by yourself. How long the downgrade will run depends on your amount of data.

[bigfoot65]

If you want to force Greyhole to do it on your schedule, you can do it via command line.

As root user (F14), do:

Code: Select all

greyhole -f

For Ubuntu, it's:

Code: Select all

sudo greyhole -f

You can monitor the log at /var/log/greyhole.log file.