CPU/memory recommendation/requirements?

[LoftyGoals19]

[I've posted this to r/BorgBackup and [email protected], but moving here per TW@]

I'm looking to run Borg server in a TrueNAS jail. The data is a plain OSX install, 10 TB of photos, videos, and archived disk images, a handful of medium-sized Git repositories, and one or two projects with large numbers (~1M) of small files (~2kb). It totals to around 15TB.

I believe the TrueNAS requirements lands me at basically any CPU that supports ECC and 16 GB of RAM. What would you add to that to make sure the Borg server has enough room to breathe?

FWIW, I'm fine with different memory allocations for initial backup and long-term use.

Thank you!

[ThomasWaldmann]

borg's memory use comes mainly from:

• repo index (borg serve side)
• chunks index (client side)
• files cache (client side)

There are formulas in the docs how to compute memory consumption, but it isn't easy as you likely do not know the amount of chunks in advance. Initially, it will consume little memory, but eats more as the amount of chunks in the repo grows (while doing the first backup). Any further backup will need about the same amount then / only grow slowly as new chunks get added.

Guess you can start with the 16GB RAM, but do not give ZFS too much of it.

[LoftyGoals19]

Interesting. I think this may be a RAM-hungry installation, then, because ZFS and TrueNAS basically say the same thing about the 16 GB.

I take it the primary pressure is RAM and not CPU?

[ThomasWaldmann]

borg serve usually does not need much CPU (the only exception being borg check repository part, when it computes crc32 over all chunks), but it needs enough memory for the repo index hashtable.

[LoftyGoals19]

Sounds good. I'll spec it out as 16 GB RAM for Borg plus whatever TrueNAS needs. Thank you!