Parity warp syncing slow

Question

This is the first time I try to install an Ethereum client and I'm trying with Parity v1.6.6 on Arch Linux (sudo pacman -S parity).

I read that the --warp option allows to save time not syncing the whole blockchain but honestly it seems still slow for my expectations...

I'm running it from 30 minutes and it's syncing snapshot 1/158, is it normal?

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Just few minutes ago it re-started from zero:

017-05-13 22:41:52  Syncing snapshot 1/158        #0    3/25/25 peers     3 MiB db    7 KiB chain  0 bytes queue   10 KiB sync  RPC:  1 conn,  5 req/s,  82 µs
2017-05-13 22:41:57  Syncing snapshot 1/158        #0    3/25/25 peers     3 MiB db    7 KiB chain  0 bytes queue   10 KiB sync  RPC:  2 conn,  6 req/s,  81 µs
2017-05-13 22:42:02  Syncing snapshot 1/158        #0    3/24/25 peers     3 MiB db    7 KiB chain  0 bytes queue   10 KiB sync  RPC:  2 conn,  5 req/s,  70 µs
2017-05-13 22:42:07  Syncing snapshot 1/158        #0    3/24/25 peers     3 MiB db    7 KiB chain  0 bytes queue   10 KiB sync  RPC:  1 conn,  6 req/s,  68 µs
2017-05-13 22:42:12  Syncing snapshot 1/158        #0    1/23/25 peers     3 MiB db    7 KiB chain  0 bytes queue   10 KiB sync  RPC:  1 conn,  6 req/s,  94 µs
2017-05-13 22:42:17  Syncing snapshot 1/158        #0    1/23/25 peers     3 MiB db    7 KiB chain  0 bytes queue   10 KiB sync  RPC:  1 conn,  5 req/s,  94 µs
2017-05-13 22:42:39  Imported #2 b495…98c9 (0 txs, 0.00 Mgas, 0.44 ms, 0.53 KiB) + another 1 block(s) containing 0 tx(s)
2017-05-13 22:42:43  Imported #986 a116…08bf (0 txs, 0.00 Mgas, 0.36 ms, 0.53 KiB) + another 1 block(s) containing 0 tx(s)
2017-05-13 22:42:45  Imported #1434 943b…9a56 (0 txs, 0.00 Mgas, 0.28 ms, 1.06 KiB) + another 2 block(s) containing 0 tx(s)
2017-05-13 22:42:46  Imported #1773 1dff…4535 (0 txs, 0.00 Mgas, 0.11 ms, 0.53 KiB)
2017-05-13 22:42:47    12/20/25 peers    12 MiB db    2 MiB chain  0 bytes queue    1 MiB sync  RPC:  1 conn,  9 req/s,  77 µs
2017-05-13 22:42:48  Imported #2794 46f3…6a0a (0 txs, 0.00 Mgas, 0.24 ms, 1.06 KiB) + another 1 block(s) containing 0 tx(s)
2017-05-13 22:42:49  Imported #2803 a6dc…6546 (0 txs, 0.00 Mgas, 0.33 ms, 0.53 KiB) + another 2 block(s) containing 0 tx(s)
2017-05-13 22:42:51  Imported #3175 a296…c4a3 (0 txs, 0.00 Mgas, 0.12 ms, 0.53 KiB) + another 1 block(s) containing 0 tx(s)
2017-05-13 22:42:52  Imported #3556 8171…3d91 (0 txs, 0.00 Mgas, 0.11 ms, 0.53 KiB) + another 2 block(s) containing 0 tx(s)
2017-05-13 22:42:53  Imported #3562 c3de…552d (0 txs, 0.00 Mgas, 0.13 ms, 0.53 KiB)
2017-05-13 22:43:02  Syncing    #5426 df06…8382   218 blk/s    0 tx/s   0 Mgas/s    284+    0 Qed     #5715    3/24/25 peers    27 MiB db    5 MiB chain  494 KiB queue  969 KiB sync  RPC:  1 conn,  5 req/s,  73 µs
2017-05-13 22:43:02  Imported #5715 e06b…95fa (0 txs, 0.00 Mgas, 0.59 ms, 0.53 KiB) + another 3 block(s) containing 0 tx(s)
2017-05-13 22:43:06  Imported #5734 7d62…9da2 (0 txs, 0.00 Mgas, 0.21 ms, 0.53 KiB)
2017-05-13 22:43:07  Imported #6223 544e…07ff (0 txs, 0.00 Mgas, 0.57 ms, 0.53 KiB) + another 3 block(s) containing 0 tx(s)
2017-05-13 22:43:27  Syncing snapshot 0/158     #6249    3/20/25 peers    29 MiB db    7 MiB chain  0 bytes queue  966 KiB sync  RPC:  1 conn,  5 req/s,  88 µs
2017-05-13 22:43:37  Syncing snapshot 0/158     #6249    3/23/25 peers    29 MiB db    7 MiB chain  0 bytes queue  966 KiB sync  RPC:  1 conn,  7 req/s,  95 µs
2017-05-13 22:43:47  Syncing snapshot 0/158     #6249    2/23/25 peers    29 MiB db    6 MiB chain  0 bytes queue  966 KiB sync  RPC:  2 conn,  5 req/s,  96 µs
2017-05-13 22:43:57  Syncing snapshot 0/158     #6249    2/22/25 peers    29 MiB db    6 MiB chain  0 bytes queue  966 KiB sync  RPC:  2 conn,  5 req/s,  88 µs
2017-05-13 22:44:00  Unauthorized connection to Signer API blocked.
2017-05-13 22:44:07  Syncing snapshot 0/158     #6249    2/21/25 peers    29 MiB db    7 MiB chain  0 bytes queue  966 KiB sync  RPC:  2 conn, 19 req/s,  90 µs
2017-05-13 22:44:17  Syncing snapshot 0/158     #6249    2/22/25 peers    29 MiB db    6 MiB chain  0 bytes queue  966 KiB sync  RPC:  1 conn,  8 req/s,  91 µs
2017-05-13 22:44:27  Syncing snapshot 0/158     #6249    1/22/25 peers    29 MiB db    6 MiB chain  0 bytes queue  966 KiB sync  RPC:  2 conn,  7 req/s,  78 µs
2017-05-13 22:44:37  Syncing snapshot 0/158     #6249    1/22/25 peers    29 MiB db    6 MiB chain  0 bytes queue  966 KiB sync  RPC:  1 conn,  6 req/s,  88 µs

that

2017-05-13 22:44:00  Unauthorized connection to Signer API blocked.

concernes me, is this about some request from the Parity UI?

Answer 1

You are either on a bad connection or you don't have enough peers which can provide you with a warp snapshot. You can add extra warp snapshot peers with:

parity --snapshot-peers 16

This will help maintaining the warp sync.

Answer 2

 run parity -lsync=trace

looking for:  "IO Worker #3 TRACE sync  Checking snapshot sync: X (peer: Y)" 

Search for the largest number Y  in (peer: Y) 
then copy X

 stop parity and remove -lsync=trace

open ".../.local/share/io.parity.ethereum/config.toml "
and update config.toml with warp_barrier = X

 run  : parity