Re: copie de fichiers lente sur RAID0 (soft)...

[fred <fredantispam@free.fr>]

fred <fredantispam@free.fr> a écrit :

> Bonjour,
>
> Après avoir lu le howto, et le manuel de mdadm, je me trouve confronté
> à un problème : la copie de fichiers est extrèmement lente, de fs non
> raid à fs raid ou de raid à raid.
>
> Pourtant, un hdparm sur les fs raid me donnent des résultats tout à fait
> corrects, puisque le taux est multiplié quasiment par deux par rapport à
> un fs non raid :
>
> /dev/md4:
>  Timing cached reads:   4500 MB in  2.00 seconds = 2250.34 MB/sec
>  Timing buffered disk reads:  378 MB in  3.01 seconds = 125.77 MB/sec
>
> Ayant plusieurs dizaines de Go à tranférer entre les fs non raid et
> raid, ça risque de prendre des jours :-(
>
> cat /proc/mdstat ne m'indique rien d'anormal (àmha) :
>
> Personalities : [raid0] 
> md4 : active raid0 sdb4[1] sda4[0]
>       72265472 blocks 64k chunks
>       
> md6 : active raid0 sda6[0] sdb6[1]
>       97656064 blocks 64k chunks
>
> Le howto précise que changer la taille des chunks n'a pas d'influence.
> Le paramètre important est la taille des blocks, qui doit être maximale
> (4 ko), ce qui est bien le cas.
>
> Je ne comprends pas.
>
> Auriez-vous une idée à ce sujet ?
Les deux disques ayant la mme rfrence (mais n'ayant pas t achet en
mme temps, qques mois d'intervalle), ils ne semblent cependant pas tout
 fait identiques (udma, queue depth...), d'aprs hdparm :
/dev/sda:

ATA device, with non-removable media
        Model Number:       Maxtor 6L250S0                          
        Serial Number:      L501LRHG            
        Firmware Revision:  BANC1G10
Standards:
        Supported: 7 6 5 4 
        Likely used: 7
Configuration:
        Logical         max     current
        cylinders       16383   16383
        heads           16      16
        sectors/track   63      63
        --
        CHS current addressable sectors:   16514064
        LBA    user addressable sectors:  268435455
        LBA48  user addressable sectors:  490234752
        device size with M = 1024*1024:      239372 MBytes
        device size with M = 1000*1000:      251000 MBytes (251 GB)
Capabilities:
        LBA, IORDY(can be disabled)
        Queue depth: 32
        Standby timer values: spec'd by Standard, no device specific minimum
        R/W multiple sector transfer: Max = 16  Current = 1
        Advanced power management level: unknown setting (0x0000)
        Recommended acoustic management value: 192, current value: 254
        DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6 
             Cycle time: min=120ns recommended=120ns
        PIO: pio0 pio1 pio2 pio3 pio4 
             Cycle time: no flow control=120ns  IORDY flow control=120ns
Commands/features:
        Enabled Supported:
           *    NOP cmd
           *    READ BUFFER cmd
           *    WRITE BUFFER cmd
           *    Host Protected Area feature set
           *    Look-ahead
           *    Write cache
           *    Power Management feature set
                Security Mode feature set
                SMART feature set
           *    FLUSH CACHE EXT command
           *    Mandatory FLUSH CACHE command 
           *    Device Configuration Overlay feature set 
           *    48-bit Address feature set 
           *    Automatic Acoustic Management feature set 
                SET MAX security extension
                Advanced Power Management feature set
           *    DOWNLOAD MICROCODE cmd
           *    General Purpose Logging feature set
           *    SMART self-test 
           *    SMART error logging 
Security: 
        Master password revision code = 65534
                supported
        not     enabled
        not     locked
        not     frozen
        not     expired: security count
        not     supported: enhanced erase
Checksum: correct

/dev/sdb:

ATA device, with non-removable media
        Model Number:       Maxtor 6L250S0                          
        Serial Number:      L50GTS8G            
        Firmware Revision:  BACE1G10
Standards:
        Supported: 7 6 5 4 
        Likely used: 7
Configuration:
        Logical         max     current
        cylinders       16383   16383
        heads           16      16
        sectors/track   63      63
        --
        CHS current addressable sectors:   16514064
        LBA    user addressable sectors:  268435455
        LBA48  user addressable sectors:  488397168
        device size with M = 1024*1024:      238475 MBytes
        device size with M = 1000*1000:      250059 MBytes (250 GB)
Capabilities:
        LBA, IORDY(can be disabled)
        Queue depth: 1
        Standby timer values: spec'd by Standard, no device specific minimum
        R/W multiple sector transfer: Max = 16  Current = 1
        Advanced power management level: unknown setting (0x0000)
        DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 *udma5 
             Cycle time: min=120ns recommended=120ns
        PIO: pio0 pio1 pio2 pio3 pio4 
             Cycle time: no flow control=120ns  IORDY flow control=120ns
Commands/features:
        Enabled Supported:
           *    NOP cmd
           *    READ BUFFER cmd
           *    WRITE BUFFER cmd
           *    Look-ahead
                Write cache
           *    Power Management feature set
                SMART feature set
           *    FLUSH CACHE EXT command
           *    Mandatory FLUSH CACHE command 
           *    Device Configuration Overlay feature set 
           *    48-bit Address feature set 
                SET MAX security extension
                Advanced Power Management feature set
           *    DOWNLOAD MICROCODE cmd
           *    General Purpose Logging feature set
           *    SMART self-test 
           *    SMART error logging 
Checksum: correct

Cela aurait-il une quelconque incidence ?

Merci.


-- 
Fred.