On 6/27/2022 3:18 PM, Richard Brittain (richard.britt...@dartmouth.edu) wrote: > I know this is a long shot, but I've got a no-quota volume of approx > 6TB, and I'm trying to replicate it. It appears to be going fine > until the packetRead counter reaches 2^64 and then it stops (doesn't > abort).
I believe you meant 2^32 packets not 2^64. > Servers are 1.6.22 (I thought I'd retire then before now, so didn't > bother upgrading to 1.8.x). If 1.8 might change this limit, I can > upgrade, but I didn't find any hints in the release notes. There are going to be two issues with moving a volume larger than 2TB. First, the volume header diskused counter is going to wrap negative above 2TB which will throw off all of the estimated counts for how much space is required on the destination and how long the transfer will require. Second, there is a hard limit in OpenAFS RX on the number of packets that can be transmitted in a single call. 2^32 - 2. > > Based on how long it ran, my guess is > 5TB was transferred. The 2^32 - 2 packets can transfer approximately 5.6TB of data. After that the call's data flow will stall and the call will be kept alive forever by PING x PING_RESPONSE exchanges. If rxkad is used to protect the call, then the maximum number of packets that can be transferred in a single call without risk of replay attacks is 2 ^ 30 - 2. Approximately 1.4TB of data. There are no checks in the rxkad code to prevent sending more than 2 ^ 30 packets. > Is this affected by volser buffer sizes ? No. Not all RX implementations have this limitation. AuriStor RX will support single calls up to 2^64 - 1 packets. Approximately 22ZB. yfs-rxgk is not susceptible to replay attacks during a call consisting of 2^64 - 1 packets. Jeffrey Altman
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