First Aid Not able to fix disk

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Hi
I have an iMac with 3 TB Fusion drive, recently I tried to use first aid in the disk utility and it said it could not repair the disk and suggested trying recovery mode. I booted to recovery mode and ran first aid but it said also it could not fix the disk. What are my options is there a good third party utility that can fix the error as I need to upgrade to High Sierra. Currently I am using Sierra and the computer boots and works fine.

Thanks
Ayman

@ayman-zekry,

I'm trying to understand the issue you're trying to solve? Is this a disk problem? I ask because in the last sentence you're writing that it's working fine and it boots. So is this the startup disk?

Is this another disk that is not the startup disk and there is a problem with the fusion drive that first aid isn't working?

Are you upgrading from the disk that is currently working on Sierra? is the upgrade you want to do on the fusion drive the fusion drive the same drive?

@ronnie-wong Hi Ronnie
Yes this is the Macintosh HD and it is the only disk I have. The disk does work fine but when I check it with first aid it gives the following error below. Yes I am upgrading from the disk that is currently working on Sierra It is working fine in Sierra (10.12.6) but when I try to upgrade to high sierra it says it can not upgrade because first aid found an error. I am running iMac late 2014.

Load and verify Logical Volumes B-Trees
Logical Volume Group contains 1 Logical Volume
Load and verify 4F473964-4F4C-43D3-9C34-10A52B766CB2
Load and verify BECB30F2-105A-4C6F-8CFA-D9A74E1371FE
Unable to bootstrap transaction group 4899081: malformed B-Tree
No valid commit checkpoint found
The volume A3B8AA0F-D611-4010-A5D6-65BA9F78A8C0 was found corrupt and needs to be repaired
Storage system check exit code is 1.

@ayman-zekry,

Sorry about the delay here. The best bet now is that something has corrupted but try rebooting to recovery mode from the internet ( cmd +opt+R) this is a longer process but it should fix it if the disk is not physically damaged.

http://www.idownloadblog.com/2016/02/25/how-to-start-up-your-mac-in-internet-recovery-mode/