tuto:linux:tunning_hdd
Différences
Ci-dessous, les différences entre deux révisions de la page.
| Les deux révisions précédentesRévision précédenteProchaine révision | Révision précédente | ||
| tuto:linux:tunning_hdd [2013/06/25 20:46] – [tuning cfq] root | tuto:linux:tunning_hdd [2016/10/27 21:15] (Version actuelle) – [Tunning HDD] root | ||
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| ====== Tunning HDD ====== | ====== Tunning HDD ====== | ||
| + | ===== mdadm ===== | ||
| + | [[https:// | ||
| ===== sysfs ===== | ===== sysfs ===== | ||
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| Spécifie si c'est un ssd (0) ou classique (1). | Spécifie si c'est un ssd (0) ou classique (1). | ||
| - | ==== tuning cfq ==== | + | ===== tuning cfq ===== |
| https:// | https:// | ||
| + | |||
| + | http:// | ||
| * **back_seek_max** : Backward seeks are typically bad for performance, | * **back_seek_max** : Backward seeks are typically bad for performance, | ||
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| * **slice_idle** : This specifies how long CFQ should idle while waiting for further requests. The default value in Red Hat Enterprise Linux 6.1 and earlier is 8 ms. In Red Hat Enterprise Linux 6.2 and later, the default value is 0. The zero value improves the throughput of external RAID storage by removing all idling at the queue and service tree level. However, a zero value can degrade throughput on internal non-RAID storage, because it increases the overall number of seeks. For non-RAID storage, we recommend a slice_idle value that is greater than 0. | * **slice_idle** : This specifies how long CFQ should idle while waiting for further requests. The default value in Red Hat Enterprise Linux 6.1 and earlier is 8 ms. In Red Hat Enterprise Linux 6.2 and later, the default value is 0. The zero value improves the throughput of external RAID storage by removing all idling at the queue and service tree level. However, a zero value can degrade throughput on internal non-RAID storage, because it increases the overall number of seeks. For non-RAID storage, we recommend a slice_idle value that is greater than 0. | ||
| * **slice_sync** : This tunable dictates the time slice allotted to a process issuing synchronous (read or direct write) I/O. The default is 100 ms. | * **slice_sync** : This tunable dictates the time slice allotted to a process issuing synchronous (read or direct write) I/O. The default is 100 ms. | ||
| + | ===== tuning deadline ===== | ||
| - | ==== tuning deadline ==== | + | http:// |
| * **fifo_batch** : This determines the number of reads or writes to issue in a single batch. The default is 16. Setting this to a higher value may result in better throughput, but will also increase latency. | * **fifo_batch** : This determines the number of reads or writes to issue in a single batch. The default is 16. Setting this to a higher value may result in better throughput, but will also increase latency. | ||
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| * **write_expire** : This tunable allows you to set the number of milliseconds in which a write request should be serviced. By default, this is set to 5000 ms (five seconds). | * **write_expire** : This tunable allows you to set the number of milliseconds in which a write request should be serviced. By default, this is set to 5000 ms (five seconds). | ||
| * **writes_starved** : This tunable controls how many read batches can be processed before processing a single write batch. The higher this is set, the more preference is given to reads. | * **writes_starved** : This tunable controls how many read batches can be processed before processing a single write batch. The higher this is set, the more preference is given to reads. | ||
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| ===== Script ===== | ===== Script ===== | ||
tuto/linux/tunning_hdd.1372193162.txt.gz · Dernière modification : 2013/06/25 20:46 de root