Il blog di Gas

No comment

Audio Test (flac)

without comments

These are some flac files to test an hi-fi equipment. Some of them are very low and high frequency, don’t turn up the volume too much with these frequencies, maybe you can’t hear them because your equipment cannot render those frequencies. If the filename is a number that is the sound frequency.

HIFI-TEST.zip

Written by gas_admin

settembre 27th, 2013 at 6:21 pm

Posted in English

Tagged with

Logcheck rules for dropbear (Debian7.1 – wheezy)

without comments

^[[:alpha:]]{3} [ :[:digit:]]{11} [._[:alnum:]-]+ dropbear\[[[:digit:]]+\]: Child connection from [.:[:xdigit:]]+:[[:digit:]]+$
^[[:alpha:]]{3} [ :[:digit:]]{11} [._[:alnum:]-]+ dropbear\[[[:digit:]]+\]: Pubkey auth succeeded for '[[:alnum:]-]+' with key md5 ([[:xdigit:]]{2}:){15}[[:xdigit:]]{2} from [.:[:xdigit:]]+:[[:digit:]]+$
^[[:alpha:]]{3} [ :[:digit:]]{11} [._[:alnum:]-]+ dropbear\[[[:digit:]]+\]: password auth succeeded for '[[:alnum:]-]+' from [.:[:xdigit:]]+:[[:digit:]]+$
^[[:alpha:]]{3} [ :[:digit:]]{11} [._[:alnum:]-]+ dropbear\[[[:digit:]]+\]: Exit \([[:alnum:]-]+\): Disconnect received$

Written by gas

settembre 27th, 2013 at 1:45 pm

Posted in English,Linux

Tagged with

Logcheck rules for rddcached (Debian7.1 – wheezy)

without comments

^\w{3} [ :[:digit:]]{11} [._[:alnum:]-]+ rrdcached\[[[:digit:]]+\]: flushing old values|rotating journals
^\w{3} [ :[:digit:]]{11} [._[:alnum:]-]+ rrdcached\[[[:digit:]]+\]: (started new|removing old) journal /var/lib/rrdcached/journal/rrd\.journal.[\.[:digit:]]{17}

To much the following in /var/log/syslog

Sep 20 18:50:28 XXXX rrdcached[24700]: flushing old values
Sep 20 18:50:28 XXXX rrdcached[24700]: rotating journals
Sep 20 18:50:28 XXXX rrdcached[24700]: started new journal /var/lib/rrdcached/journal/rrd.journal.1379695828.566583
Sep 20 18:50:28 XXXX rrdcached[24700]: removing old journal /var/lib/rrdcached/journal/rrd.journal.1379688628.566927

Written by gas

settembre 20th, 2013 at 6:15 pm

Posted in English,Linux

Tagged with

OVH vs Prometeus VPS

without comments

I tested two vps, one from ovh the other from an italian company that advertised a coupon on lowendbox.com. Both servers have two cores and 512 MB of RAM, OVH cloud vps is about 10 € a month while Prometeus BIZ Xen 5 is 7€.

dd bs=1M count=512 if=/dev/zero of=test conv=fdatasync

OVH: 536870912 bytes (537 MB) copied, 81.8946 s, 6.6 MB/s

Prometeus: 536870912 bytes (537 MB) copied, 1.92747 s, 279 MB/s

sysbench –test=cpu –cpu-max-prime=20000 run

OVH: 26s

Prometeus: 44s

sysbench –test=memory –memory-total-size=1G run

OVH:1286.34 MB/sec

Prometeus: 238.80 MB/sec

 

OVH server had a very bad I/O…really rally bad while the CPU and RAM were faster than Prometeus

I think I’ll stick with Prometeus for a wordpress blog, the feeling I had is that it’s quicker. Regardless of the good rates I had by downloading and uploading files, OVH vps was much slower in serving images for some reasons. Slower means “some seconds” more in loading a standard home page with 5-6 locally stored images. With OVH I had a couple of reboots in 3 weeks

Prometeus also gives you a small backup space on a different data center, while with OVH there is no backup included in their plans.

Written by gas

settembre 12th, 2013 at 7:04 pm

Posted in English

Tagged with , , ,

end_request i/o error

without comments

Oggi mi son trovato questo errore nei file di log.

end_request: I/O error, dev sdd, sector 1503894851
Buffer I/O error on device sdd1, logical block 751947394

Il problema era della partizione sdd1, che io monto su /media/Archivio

smartctl -a /dev/sdd
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  5 Reallocated_Sector_Ct   0x0033   100   100   036    Pre-fail  Always       -       0
197 Current_Pending_Sector  0x0012   100   099   000    Old_age   Always       -       52
198 Offline_Uncorrectable   0x0010   100   099   000    Old_age   Offline      -       52

e a quanto pare non era l’unico ma ce ne erano altri 51.

Leggendo in giro sui forum si dice che in questi casi sarebbe meglio cambiare hard disk. Io non ci credo molto, almeno finchè il conteggio dei settori reallocati rimane a 0 (la prima riga, 5 Reallocated_Sector_Ct).

e2fsck -c -c fa un controllo non distruttivo sulla partizione per i “badblocks”, sun un hard disk relativamente recente ci mette circa 13 ore ogni TB di dati.
e2fsck -c -c /dev/sdd1
e2fsck 1.42.7 (21-Jan-2013)
Checking for bad blocks (non-destructive read-write test)
Testing with random pattern: done
Archivio: Updating bad block inode.
Pass 1: Checking inodes, blocks, and sizes
Running additional passes to resolve blocks claimed by more than one inode...
Pass 1B: Rescanning for multiply-claimed blocks
Multiply-claimed block(s) in inode 2251: 187891582 187891756 187891930 187892104 187892278 187892668 187892842 187893016 187893190 187893364 187893539 187893929 187894103 187894277 187926790 187927180 187927354 187927355 187927528 187927702 187927703 187927876 187927877 187928266 187928267 187928440 187928441 187985860 187986034 187986208 187986382 187986500 187986556 187986674 187986848 187986946 187987022 187987120 187987196 187987294 187987468 187987642 187987760 187987816 187987934 187988108 187988206 187988282 187988380 187988554 187988672 187988728
Pass 1C: Scanning directories for inodes with multiply-claimed blocks
Pass 1D: Reconciling multiply-claimed blocks
(There are 1 inodes containing multiply-claimed blocks.)
File /Movie.mkv (inode #2251, mod time Mon Sep 9 00:06:30 2013)
has 52 multiply-claimed block(s), shared with 1 file(s):

Non se le due cose siano legate ma e2fsck mi ha trovato anche “multiply-claimed blocks”, 52, e mi ha chiesto se volevo correggerli, io ho selezionato no. Ho cancellato il file dato che non mi interessava (File /Movie.mkv). Così facendo i “badblocks” sono andati a finire nello spazio libero della partizione che ho riempito di zeri (da root)
cat /dev/zero >/Media/Archivio/zero
rm /Media/Archivio/zero

Fatto questo sembra essere tornato tutto apposto.

smartctl -a /dev/sdd
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  5 Reallocated_Sector_Ct   0x0033   100   100   036    Pre-fail  Always       -       0
197 Current_Pending_Sector  0x0012   100   099   000    Old_age   Always       -       0
198 Offline_Uncorrectable   0x0010   100   099   000    Old_age   Offline      -       0

Sperem….

Written by gas

settembre 9th, 2013 at 7:18 pm

Posted in Linux

Tagged with