Will SSD cache improve array rebuild speed?

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Merdon
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Will SSD cache improve array rebuild speed?

Unread post by Merdon » Thu May 17, 2018 11:37 pm

Hi, I currently have an DS1817+ (16GB) and I am using all 8 drives. One volume using SHR2 (ext4)

However, some of the HDD's are getting pretty old so I'm thinking of replacing them one at a time before any issues occurs. This will of course take some time so before doing that I'm also thinking about setting up some SSD cache with M2D17 (the M.2 SSD adapter).

Will the use of SSD cache improve the rebuild speed of the raid?

sincarne
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Re: Will SSD cache improve array rebuild speed?

Unread post by sincarne » Fri May 18, 2018 7:40 am

no, what data it would cache during rebuild?

Squozen
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Re: Will SSD cache improve array rebuild speed?

Unread post by Squozen » Fri May 18, 2018 9:56 am

Not only will it not improve speed (a rebuild is always going to be limited to the speed of the drives in the array), if Synology has implemented the cache properly it shouldn't even try to cache data during a rebuild.

Merdon
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Re: Will SSD cache improve array rebuild speed?

Unread post by Merdon » Fri May 18, 2018 3:57 pm

Thanks for the answers! Well, it only makes sense not to cache while rebuilding when you think about it.

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