Bitcoin Core v29.0 incorrectly enters IBD mode when only ~600 blocks behind, preventing normal sync

anhilde commented at 2:30 pm on July 12, 2025: none

Is there an existing issue for this?

I have searched the existing issues

Current behaviour

Hi, I have a full node on a development machine that is not always run. It runs a self compiled none modified v29.0 node as systemd service on an Ubuntu 24.04 system. I had it twice now that the node, after not using it for a few days would go into IBD mode. This time I tried rebuilding the chain state but it would only go as far as the same block it was stuck on before. By running bitcoin-cli -conf=/mnt/btc/.bitcoin/bitcoin.conf reconsiderblock 000000000000000000009d1dd2f71099471a348f4074285707b17e0588c41002 it would synced 48 blocks to then get stuck again. Running reconsiderblock again using bitcoin-cli -conf=/mnt/btc/.bitcoin/bitcoin.conf reconsiderblock $(bitcoin-cli -conf=/mnt/btc/.bitcoin/bitcoin.conf getbestblockhash) did not trigger the sync to continue. After restarting with parameters -minimumchainwork=0 -maxtipage=31536000 it is now syncing again normally.

Expected behaviour

Should sync normally without manual intervention

Steps to reproduce

Turn of the PC normally and let it fall behind a few days. I cannot say how reproducible this is since it only happened twice so far and it does not happen often that the machine is not used for more than ~12 hours. With shorter times offline it seems not to happen.

Relevant log output

This is my startup log from a try where it was in IBD:

Jul 12 10:48:31 linuxpc systemd[1]: Starting bitcoind.service - Bitcoin Daemon… Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Bitcoin Core version v29.0 (release build) Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using the ‘x86_shani(1way,2way)’ SHA256 implementation Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using RdSeed as an additional entropy source Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using RdRand as an additional entropy source Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Default data directory /nonexistent/.bitcoin Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using data directory /mnt/btc/.bitcoin Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file: /mnt/btc/.bitcoin/bitcoin.conf Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: bind=“0.0.0.0” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: checkblocks=“24” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: checklevel=“0” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: dbcache=“8000” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: listen=“1” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: maxconnections=“24” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: port=“8333” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: rpcallowip=“192.168.1.0/24” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: rpcbind=“0.0.0.0” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: rpcpassword=**** Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: rpcport=“8332” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: rpcuser=**** Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: server=“1” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config file arg: txindex=“1” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Setting file arg: wallet = [“cormorant”] Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Command-line arg: conf="/mnt/btc/.bitcoin/bitcoin.conf" Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Command-line arg: datadir="/mnt/btc/.bitcoin" Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Command-line arg: startupnotify=“systemd-notify –ready” Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using at most 24 automatic connections (65535 file descriptors available) Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z scheduler thread start Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Binding RPC on address 0.0.0.0 port 8332 Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z WARNING: the RPC server is not safe to expose to untrusted networks such as the public internet Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Config options rpcuser and rpcpassword will soon be deprecated. Locally-run instances may remove rpcuser to use cookie-based auth, or may be replaced with rpcauth. Please see share/rpcauth for rpcauth auth generation. Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Starting HTTP server with 16 worker threads Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using wallet directory /mnt/btc/.bitcoin Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z init message: Verifying wallet(s)… Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using SQLite Version 3.45.1 Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using wallet /mnt/btc/.bitcoin/cormorant Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using /16 prefix for IP bucketing Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z init message: Loading P2P addresses… Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Loaded 67617 addresses from peers.dat 132ms Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z init message: Loading banlist… Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z SetNetworkActive: true Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Cache configuration: Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z * Using 2.0 MiB for block index database Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z * Using 1000.0 MiB for transaction index database Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z * Using 8.0 MiB for chain state database Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z * Using 6990.0 MiB for in-memory UTXO set (plus up to 286.1 MiB of unused mempool space) Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Script verification uses 15 additional threads Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using obfuscation key for blocksdir *.dat files (/mnt/btc/.bitcoin/blocks): ‘cb7f2abf983a0e66’ Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Opening LevelDB in /mnt/btc/.bitcoin/blocks/index Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Opened LevelDB successfully Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using obfuscation key for /mnt/btc/.bitcoin/blocks/index: 0000000000000000 Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using 16 MiB out of 16 MiB requested for signature cache, able to store 524288 elements Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Using 16 MiB out of 16 MiB requested for script execution cache, able to store 524288 elements Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z init message: Loading block index… Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Assuming ancestors of block 00000000000000000001b658dd1120e82e66d2790811f89ede9742ada3ed6d77 have valid signatures. Jul 12 10:48:31 linuxpc bitcoind[335661]: 2025-07-12T13:48:31Z Setting nMinimumChainWork=0000000000000000000000000000000000000000b1f3b93b65b16d035a82be84 Jul 12 10:48:34 linuxpc bitcoind[335661]: 2025-07-12T13:48:34Z LoadBlockIndexDB: last block file = 5021 Jul 12 10:48:34 linuxpc bitcoind[335661]: 2025-07-12T13:48:34Z LoadBlockIndexDB: last block file info: CBlockFileInfo(blocks=45, size=62616878, heights=904539…904606, time=2025-07-08…2025-07-08) Jul 12 10:48:34 linuxpc bitcoind[335661]: 2025-07-12T13:48:34Z Checking all blk files are present… Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Initializing chainstate Chainstate [ibd] @ height -1 (null) Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Opening LevelDB in /mnt/btc/.bitcoin/chainstate Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Opened LevelDB successfully Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Using obfuscation key for /mnt/btc/.bitcoin/chainstate: 922d01a00a52f620 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Loaded best chain: hashBestChain=000000000000000000009d1dd2f71099471a348f4074285707b17e0588c41002 height=904558 date=2025-07-08T05:32:02Z progress=0.998569 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z init message: Verifying blocks… Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verifying last 24 blocks at level 0 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 0% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 12% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 20% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 33% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 41% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 50% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 62% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 70% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 83% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification progress: 91% Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Verification: No coin database inconsistencies in last 24 blocks (0 transactions) Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Block index and chainstate loaded Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Opening LevelDB in /mnt/btc/.bitcoin/indexes/txindex Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Opened LevelDB successfully Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Using obfuscation key for /mnt/btc/.bitcoin/indexes/txindex: 0000000000000000 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Using SQLite Version 3.45.1 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Using wallet /mnt/btc/.bitcoin/cormorant Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z init message: Loading wallet… Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z [cormorant] Wallet file version = 10500, last client version = 290000 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z [cormorant] Descriptors: 0, Descriptor Keys: 0 plaintext, 0 encrypted, 0 total. Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z [cormorant] Wallet completed loading in 0ms Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z [cormorant] setKeyPool.size() = 0 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z [cormorant] mapWallet.size() = 0 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z [cormorant] m_address_book.size() = 0 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Setting NODE_NETWORK on non-prune mode Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z block tree size = 904607 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z nBestHeight = 904558 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z initload thread start Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Bound to 0.0.0.0:8333 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z torcontrol thread start Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Loaded 0 addresses from “anchors.dat” Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Loading 14572 mempool transactions from file… Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z txindex thread start Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z 0 block-relay-only anchors will be tried for connections. Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z init message: Starting network threads… Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z net thread start Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z addcon thread start Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z dnsseed thread start Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Waiting 300 seconds before querying DNS seeds. Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z init message: Done loading Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z opencon thread start Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z msghand thread start Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z txindex is enabled at height 904559 Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z txindex thread exit Jul 12 10:48:35 linuxpc systemd[1]: Started bitcoind.service - Bitcoin Daemon. Jul 12 10:48:35 linuxpc bitcoind[335661]: 2025-07-12T13:48:35Z Progress loading mempool transactions from file: 10% (tried 1458, 13114 remaining) Jul 12 10:48:36 linuxpc bitcoind[335661]: 2025-07-12T13:48:36Z Progress loading mempool transactions from file: 20% (tried 2915, 11657 remaining) Jul 12 10:48:36 linuxpc bitcoind[335661]: 2025-07-12T13:48:36Z Progress loading mempool transactions from file: 30% (tried 4372, 10200 remaining) Jul 12 10:48:36 linuxpc bitcoind[335661]: 2025-07-12T13:48:36Z New outbound-full-relay v2 peer connected: version: 70016, blocks=905230, peer=0 Jul 12 10:48:36 linuxpc bitcoind[335661]: 2025-07-12T13:48:36Z Progress loading mempool transactions from file: 40% (tried 5829, 8743 remaining) Jul 12 10:48:37 linuxpc bitcoind[335661]: 2025-07-12T13:48:37Z Progress loading mempool transactions from file: 50% (tried 7286, 7286 remaining) Jul 12 10:48:37 linuxpc bitcoind[335661]: 2025-07-12T13:48:37Z Progress loading mempool transactions from file: 60% (tried 8744, 5828 remaining) Jul 12 10:48:37 linuxpc bitcoind[335661]: 2025-07-12T13:48:37Z New outbound-full-relay v1 peer connected: version: 70016, blocks=905230, peer=1 Jul 12 10:48:37 linuxpc bitcoind[335661]: 2025-07-12T13:48:37Z Progress loading mempool transactions from file: 70% (tried 10201, 4371 remaining) Jul 12 10:48:37 linuxpc bitcoind[335661]: 2025-07-12T13:48:37Z Progress loading mempool transactions from file: 80% (tried 11658, 2914 remaining) Jul 12 10:48:37 linuxpc bitcoind[335661]: 2025-07-12T13:48:37Z Progress loading mempool transactions from file: 90% (tried 13115, 1457 remaining) Jul 12 10:48:37 linuxpc bitcoind[335661]: 2025-07-12T13:48:37Z Imported mempool transactions from file: 14572 succeeded, 0 failed, 0 expired, 0 already there, 0 waiting for initial broadcast Jul 12 10:48:37 linuxpc bitcoind[335661]: 2025-07-12T13:48:37Z initload thread exit Jul 12 10:48:37 linuxpc bitcoind[335661]: 2025-07-12T13:48:37Z New outbound-full-relay v1 peer connected: version: 70016, blocks=905230, peer=2 Jul 12 10:48:38 linuxpc bitcoind[335661]: 2025-07-12T13:48:38Z New outbound-full-relay v1 peer connected: version: 70016, blocks=905230, peer=3 Jul 12 10:48:39 linuxpc bitcoind[335661]: 2025-07-12T13:48:39Z New outbound-full-relay v1 peer connected: version: 70016, blocks=905230, peer=4

How did you obtain Bitcoin Core

Compiled from source

What version of Bitcoin Core are you using?

v29.0

Operating system and version

Ubuntu 24.04 LTS

Machine specifications

Ryzen 7 5700G, 64GB Ram, NVME Disks, wired network with 550Mbit Optical Fibre Internet with good reliable connection.

soosho commented at 11:48 am on July 13, 2025: none

up

pinheadmz commented at 11:51 am on July 13, 2025: member

What’s the issue here? What do you consider “IBD” and “normal sync”?

anhilde commented at 1:22 am on July 14, 2025: none

It goes into Initial Block download mode although it has completed that before. So after restart I would expect it syncs up to the latest block, but it does not do so. It does not sync at all although it has peers and good connection. Only employing the steps described above makes it sync up to the latest block and then continue processing blocks.

sipa commented at 1:27 am on July 14, 2025: member

What does the getchaintips RPC report when it’s stuck?

I think the IBD you observe is a red herring; Bitcoin Core should always sync with the chain, whether it’s in IBD or not. IBD just modifies a few heuristics to favor bulk processing.

anhilde commented at 2:39 am on July 14, 2025: none

That makes sense, I will check it, when it gets stuck again. It may take some time until that happens. I have had it happen about twice in 2 months.

maflcko commented at 6:22 am on July 14, 2025: member

This is my startup log from a try where it was in IBD:

It looks like the log is truncated. It would be good to include the next 20 minutes as well, as it is possible you have hit a peer timeout, which can happen normally and is also handled normally (after the timeout), without the need for user intervention.

anhilde commented at 3:49 pm on July 14, 2025: none

ok, I will look out for that the next time. I am pretty sure the node was up a few hours before I noticed that the block number had not changed. What is the normal time until a node must have resumed syncing again? Is there a timeframe where I can be sure something is wrong?

sipa commented at 3:59 pm on July 14, 2025: member

It should literally always be syncing. If it doesn’t pick up an announced block immediately (within seconds, at the very longest), there is something wrong.

maflcko commented at 7:37 am on July 15, 2025: member

stalling probably doesn’t apply here, if it is less than 600 blocks, but a remote timeout can still be hit: (which is variable, but in your case could be 10 minutes)

https://github.com/bitcoin/bitcoin/blob/b53fab1467fde73c40402e2022b25edfff1e4668/src/net_processing.cpp#L5844-L5873

getpeerinfo should give an "inflight" array of blocks for each peer.

Aditya-PS-05 commented at 5:21 pm on July 19, 2025: none

I think, the main problem is in the IBD detection logic in ChainstateManager::IsInitialBlockDownload()

https://github.com/bitcoin/bitcoin/blob/master/src/validation.cpp#L2035

here, the max_tip_age defaults to 24 hours. When a node is offline for “a few days” and restarts ~600 blocks behind, the tip is older than 24 hours, incorrectly triggering IBD mode.

I think this can be solved by modifying IBD detection to consider both tip age and block distance.

sipa commented at 5:32 pm on July 19, 2025: member

here, the max_tip_age defaults to 24 hours. When a node is offline for "a few days" and restarts ~600 blocks behind, the tip is older than 24 hours, incorrectly triggering IBD mode.

It should be in IBD mode in this case.

Aditya-PS-05 commented at 7:06 pm on July 19, 2025: none

here, the max_tip_age defaults to 24 hours. When a node is offline for “a few days” and restarts ~600 blocks behind, the tip is older than 24 hours, incorrectly triggering IBD mode.

It should be in IBD mode in this case.

You’re absolutely right that IBD mode should sync.

Aditya-PS-05 commented at 7:17 pm on July 19, 2025: none

It should be in sync but I guess it can’t due to highly restrictive block download logic. IBD mode’s overly restrictive block download logic https://github.com/bitcoin/bitcoin/blob/master/src/net_processing.cpp#L5915

prevents syncing when no preferred download peers are available, causing complete sync failure despite having connected peers.

willcl-ark added the label P2P on Jan 23, 2026

willcl-ark added the label Net on Jan 23, 2026

Bitcoin Core v29.0 incorrectly enters IBD mode when only ~600 blocks behind, preventing normal sync #32955