یکی از نوشتههایی که سالها در پیشنویسهای من مانده است، نوشتهای کوتاه در مورد هارد دیسکها (برای به کارگیری در سرورها) و مقایسه کوتاهی بین آنهاست. نوشتهای در یکی از بلاگهای اچدیاس هیتاچی منتشر شده است، که خواندن آن برای همگی واجب است. در اختصار هارد دیسکهایی که هماکنون قابلیت به کار گیری دارند را بررسی کرده است و سپس تاثیر هر یک از آنها را برای کاربردهای مختلف بررسی کرده است.
- ۷۲۰۰ RPM LFF
- Today’s capacity point is 2 TB. This is available in both SATA and SAS versions on the AMS2000 family, and in a SATA version on the USP V and VSP.
- This platform is actively under development: ۳ TB SATA models are already available in retail stores from multiple vendors, and SAS 3 TB models are expected soon.
- 7200 RPM SFF
- Both the VSP and AMS2000 product lines support 7200 LFF drives which have twice the capacity, so for now we are offering only the LFF 7200 RPM models.
- 10K LFF
- Long dead.
- 10K SFF SAS
- Today’s capacity points are 300 GB and 600 GB.
- This form factor is currently the mainstream platform in enterprise HDDs, so we expect higher capacity 10K SFF models over time.
- 15K LFF
- The ۱۵K 600 LFF drive was the end of the line, and no higher capacity 15K LFF drives are expected.
- 15K SFF SAS
- Today’s capacity point is 146 GB
- Seagate has a 300 GB drive but we are not carrying this product because it is twice as expensive as a 10K RPM 300 GB SFF drive, but has much less than twice the performance.
- Hitachi GST says they plan no further 15K SFF drives at this time.
شاید در مورد هاردهایی که از تکنولوژی SSD استفاده میکنند، اطلاعات کمی در اختیار شما بگذارد، اما مطالبی که در مورد نحوه محاسبه IOPS بیان کردهاست، خواندنی و کاربردی است. این نوشته را در Putting HDD Product Trends Into Perspective: A Subsystem View بخوانید.
When talking about tunneling, different definitions come to people’s minds. Basically, tunneling is transmitting data that is encapsulated into a pipe, over a public network (for example, the Internet). However, there are different methods to tunnel data over a public network for different approaches. For example, when security is a concern, tunnel protocols with cryptography are more favorable. But when performance has higher priority, protocols with lower packet overheads will be chosen. FreeBSD 7 has a built-in support for a number of important tunneling protocols, although there are also many third-party applications in FreeBSD packages that support more tunneling protocols.
